My take on the Horizon documentary ‘Sugar v Fat’

Last night a BBC documentary aired called ‘Sugar v Fat’. If you’re in the UK, you can watch it here. The show charted the experiences of identical twin doctors in their (I think) mid-30s, who were put on very different diets for a period of 30 days. One ate a very fat-rich diet, while the other ate on rich in carbs (sugar and starch). From now on, I will refer to them as ‘High-fat’ and ‘High-carb’ for ease.

A basic premise behind the show is that identical twins have identical DNA. So, having twins eating different diets is akin to testing two diets in the same person at the same time.

The twins underwent experiments over the course of the month. At one point, for instance, the twins’ mental powers were put to the test through a simulated stock trading exercise. ‘High-fat’, apparently, fared much worse than ‘High-carb’ here.

The men were fed breakfasts consistent with their new diets, and equal in calories. 3 hours later ‘High-carb’ seemed hungrier than his sibling, and ate more at a free buffet too.

The men were exercised on bikes and then made to race up a hill. ‘High-fat’ was given a pat of butter before the race, while ‘High-carb’ got a carbohydrate gel. ‘High-carb’ won the race by a country mile.

At the end of the experiment, ‘High-fat’ had lost about 4 kg, about 1.5 kg of which was fat. ‘High-carb’ lost 1 kg in weight, about half of which was fat and half lean tissue (muscle).

Finally, the men underwent a ‘glucose tolerance test’. From what I could make out, ‘High-carb had maintained blood sugar control as a result of increased insulin secretion. ‘High-fat’ was told his glucose tolerance was worse, and that he was not far from being ‘pre-diabetic’. Much was made of this.

In the end, the conclusion was (basically), that it’s not either fat nor sugar that causes obesity, it’s overeating. We were told that foods with a combination of fat and sugar that are highly palatable and rewarding that drive people to overeat.

The fundamental problem with this programme is that it essentially dressed up anecdote as science. It’s not a good idea to judge the impact of different diets by testing them on a limited number of people in this way. It’s not much different from someone could claiming that ‘smoking never did me any harm’. And they might be right, but I’d hesitate before using that observation as the basis for advice I might give about the health effects of smoking.

The programme did point out that we cannot necessarily extrapolate the twins’ experience to the general population. That’s right, but unfortunately, I expect that is what literally millions of people may do as a result of viewing this programme.

Even the idea that testing different diets in identical twins is especially insightful is flawed. That’s because other factors beyond the twins’ DNA may have impacted on their physiological functioning. For example, ‘High-fat’ underwent mental testing in New York, while ‘High-carb’ was in London. A ton of potential factors that have nothing to do with ‘macronutrient ratios’ in the diet may have accounted for any differences in performance, including jet-lag, hydration status and the type and amount of light in the room.

‘High-carb’ stated with absolute certainty that it was his carb-fuelled breakfast that gave him the edge over his fat-munching brother. In reality, though, there is absolutely no way he could know that at all.

After the glucose tolerance test (about 38 minutes into the show) ‘High-carb’ is told he he’s making more insulin and handling sugar better. When the person officiating over the tests (Dr Richard Mackenzie from the University of Westminster in London) is pressed (by ‘High-fat’) as to whether this is a good thing, he conceded that in the long term, this could lead to problems. Of course it could, because producing more insulin to regulate blood sugar sounds likes ‘insulin resistance’ is here or on its way. Insulin resistance, by the way, is usually the key underlying factor in type 2 diabetes.

Yet, the boys end up almost rejoicing in this result, somehow. And Dr Mackenzie gives ‘High-carb’ a clean bill of health.

He had stern words for ‘High-fat’, though. He is told he is dire straights and close to being ‘pre-diabetic’. Why, because his fasting blood glucose had gone from 5.1 mmol/l to 5.9 mmol/l. But is this difference statistically significant? And could anything else have caused the rise? Stress? Running down the street on the way to the appointment? Being a bit sleep deprived?

But none of this could stop Dr Mackenzie telling ‘High-fat’ that he must stop his diet and that if he continues his pancreas is going to stop producing insulin.  Curiously, ‘High-fat’s glucose tolerance test results were not described at all. If he seemed to be in such bad shape, how come we only got to hear about his fasting test result?

I have to say, I got more of a sense of anti-fat bias through this show. The glucose tolerance testing episodes is a case in point. Also, when nutritionist Amanda Ursell was talking the boys through the diets at the start, we heard all about the bad breath and constipation ‘High-fat’ would inevitably suffer. In contrast, we heard not a peep about the potential adverse effects of a diet rammed full of sugar and fast sugar-releasing starches (such as blood sugar dysregulation and its tendency to induce mood instability, fatigue, sweet cravings and to disrupt sleep).

If the twins and the producers and Dr Mackenzie wished to genuinely gauge the impact different diets have on health, they could have looked to an abundance of published studies. This review of 23 relevant studies show quite clearly that, overall, low-carb diets produce better results regarding weight loss and disease markers (including those for type 2 diabetes).

This programme did not draw on this research, and was essentially a piece of theatre. While I found the twins very funny at times, I reckon the show was actually a tragedy.

225 Responses to My take on the Horizon documentary ‘Sugar v Fat’

  1. Jose 30 January 2014 at 5:08 pm #

    Totally agree with you was a tad disappoint. Because so many folks are doing great with LC.

    What I say to folk now to keep me getting too upset.

    Is do it for yourself for one month fully and if you don’t feel better then chuck it

    • Emma 10 February 2014 at 10:14 am #

      Just one more point… The high fat twin seemed to be eating a very high proportion of proteins to actual fats therefore digestion would be totally out of kilt as would his kidneys. Is this why his readings were high and pre-diabetic or was he in a state of ketoacidosis. Also in my limited scientific knowledge do proteins break down into amino acids then glucose? The test would have been better if both twins had the same protein and vegetables but one eating more sugar and the other fats. What confused me was that it was stated by Chris or Xand (can’t remember now) ” it is now recognised that fats are not so demonised as previously thought” however by the end of the programme you were left thinking fats are bad and sugars okay.

  2. David 30 January 2014 at 5:10 pm #

    I don’t thing less than a month was long enough to truly “keto adapt” before testing athletic performance. I suffered a brain fog in the first 2 months of a ketogenic diet but as I had read Phinneys and Voleks papers and books I pushed on and between 6 weeks and 2 months I had boundless energy and mental clarity. I agree with you totally on this programme.

    I actually tried to open a dialogue with the twins on twitter but all they do is retweet all the comments about how good looking and amusing they and the rats were!

  3. Stuart 30 January 2014 at 5:18 pm #

    Good write up John. Not sure if it was a tragedy or a comedy?

    • Emma 10 February 2014 at 9:04 am #

      I think a bit of both. What a shocker that these doctors are so ignorant with regard to diet in relation to health. Whoever has been fortunate enough to read the brilliant work of Weston A Price (nutrition and physical degeneration), Sally Fallon (nourishing traditions) and Sarah Wilson (i quit sugar) will know the profound effects that sugars have on the body. Come on Horizon – if you want to show some good scientific research please actually DO some and back it up with research already done as there is plenty out there. AND I think everyone with half a brain already knows that cheesecake, trans fats (which incidentally the high carb twin had plenty) is not a good thing and what about the source of the foods. Was the meat organic from grass fed produce? I think an opportunity has been sadly missed to overturn the myth that properly sourced saturated fats are a necessity for well being. People will now think sugar is okay…. So sad…

  4. Dr Mackenzie 30 January 2014 at 5:40 pm #

    You write very interestingly. I assume this is for impact to ensure people read your work? All 3 of us within the show do publish work with myself specifically in diabetes – maybe you should check this out first before writing this stuff. A note of worth – insulin resistance, why key to diabetes development, is not proved to be the key factor and it is more likely that hepatic insulin resistance is the fundamental in this development. From what I can tell for reading this is that you feel glucose is an issue? That’s interesting. Have you published anything recently around this – i would be genuinely interested to read it if so.

    • Garry Lee 4 February 2014 at 5:41 pm #

      You cast serious doubt on the safety in Diabetes of this diet, when in fact, the exact opposite is true. Patients do better on LCHF than on any other diet and in one series, 47% got off their oral medication compared to 11% on a diabetic diet. On very criterion they do better, weight, HBA1c, resting blood sugar and blood lipids. I’m afraid you’re looking at a small theoretical picture when there’s a huge one staring you in the face. Publishing scientific papers is to be praised, but having an overall view of a topic is something even more valuable.

    • ivor 9 February 2014 at 4:49 pm #

      Hi Dr Mackenzie

      Congratulations for being part of producing the most risible trash I’ve ever seen masquerade as science – I used to watch Horizon many years ago, and am shocked at what it has become, based on this twaddle.

      Considering the literacy and content value of your message above, commenting would not be worthwhile; however, to suggest that


      * Why was the “Fat” twin only 4.7mmol/L in the time=0 blood glucose before the cycling test??? How did you get him up to 5.9 in the fasting state – late night maybe? Or the many other ways this can occur?
      * What were the full OGTT results for the Fat twin? (we know the other guy is on the way to IR as expected – your dancing around the “body is better at producing Insulin” anti-science was high medical farce)

      I recommend some further studies in biochemistry and endocrinology before you grace the screen with your presence again…

  5. Jeff 30 January 2014 at 5:44 pm #

    How ridiculous. Maybe it’s possible that it takes longer than 30 days to become fat-adapted? How about doing it for 6 months and testing? I can’t believe they call this kind of thing science.

  6. Jennifer 30 January 2014 at 5:51 pm #

    John, you have described the pantomine succinctly. The conclusions frightened me into thinking I have been doing the wrong thing for the last year i.e. Very low carb, high fat, moderate protein. It took my husband the rest of the evening to talk me through the idiocy of this very poor BBC documentary.
    1) Lustig’s contribution was trivialised…..located in a fun fair with silly music. ( so he must be barmy)
    2) Jebb was shown as a white-coated academic in a university setting. ( so she must be sensible)
    3) there is much psychology in the tactics of a bike race, having far more impact than just diet….and how many of us race around on bikes!
    4)the theatrical effects of ‘researchers’….e.g. whispering into the camera, were laughable.
    5) we were denied actual statistics, and the ones used were unrealistic anyway.
    6) the contributors entered the zone with pre-conceived perceptions, none of which were accurate.
    7) as a school science experiment, my teachers would have scored me nought out of ten for the stupid conclusions, which were inaccurate, being ‘mere hunches’.
    8) these ‘academics’ showed very little up to date knowledge about physiology.

    Where do we go from here? I have been telling my lovely family how my husband and I have reached the wonderful state of good health we enjoy now. They must all have doubts now as to whether we are doing our selves more harm than good, despite me coming off all medications for diabetes, hypertension and raised cholesterol levels, and between the 2 of use, shedding 5 stones in a year.

    The impact of the good old BBC cannot be dismissed. It will have done immeasurable harm.

  7. Jeff 30 January 2014 at 5:56 pm #

    Impaired glucose tolerance in low-carbohydrate diet: maybe only a physiological state

    “For that reason, it should be common in clinical practice that patients submitted to oral glucose tolerance tests not be under severe carbohydrate restriction, since this could alter the response to the glucose overload. Thus, we suggest that the results from Bielohuby et al. (1) can be interpreted as a unique and not necessarily harmful metabolic condition, which is characteristic of this state, besides being transitory. As demonstrated by Kinzig et al. (4), the glucose intolerance and the peripheral insulin resistance are rapidly reversible with the reintroduction of carbohydrates in the diet.

    Additionally, the condition of induced insulin resistance is different from that induced by mitochondrial dysfunction, caused by oxidative stress generated by the glucose overload (3), which evidently does not occur with the carbohydrate restriction. In that context, ketogenic diets have not yet demonstrated adverse effects in the mitochondrial function; on the other hand, in vivo and in vitro physiological concentrations of β-hydroxybutyrate, a ketone body, increased the resistance to oxidative stress, according to a recent publication (9). It has also been demonstrated that ketogenic diets have the capacity to increase the concentrations of adiponectin, which is an important anti-inflammatory agent (5), whereas β-hydroxybutyrate stimulates the secretion of adiponectin through the activation of the hydroxycarboxylic acid receptor 2 (6).

    Therefore, we conclude that the work of Bielohuby et al. (1) is a good example of the malleability of the in vivo response to insulin, which can be modulated to benefit the current metabolic state, and that the results found are not necessarily equivalent to those found in pathological processes.”

  8. Dr John Briffa 30 January 2014 at 5:57 pm #

    Dr Mackenzie

    No, I haven’t published anything in the scientific literature about this. Does that preclude me. somehow, from having an informed opinion?

    Do you think that because you publish in the area you MUST be right, and are somehow immune from having your views or (I think) bias challenged?

    While I have not published in this area, I do have some clinical experience. Here’s what I find: When individuals with type 2 diabetes or pre-diabetes scale back on carbohydrate, almost all of them see very improved glycaemic control and much lower requirement for medication. Some are able to come off it entirely.

    What’s your clinical experience with these conditions? Do you treat individuals with diabetes and pre-diabetes? Have you ever tried carbohydrate controlled diets in such people, and if so, what were the clinical results you saw?

    Do you think the twin on the high-carb diet was at risk of developing insulin resistance?

    What were the glucose tolerance test results for the other twin? It seems your opinion in the programme was based solely on his fasting glucose level. Do you accept this can be affected by factors other than diet?

    p.s. I’m not sure what point you’re making about me writing ‘interestingly’. I write to inform, not for impact. Just because I can perhaps string a sentence together does not invalidate my arguments or mean I have forsaken substance for style.

    • ivor cummins 9 February 2014 at 4:30 pm #

      Hi Dr. Briffa

      Excellent post, the glucose segment in the “documentary” was particularly disgraceful, and I have posted elsewhere on it particularly.

      One thing I only realized later was that the cycling test had a hidden gem in it – they showed both twin’s time=0 glucose level. Sugar Boy was 4.8 and Fat Boy was………..4.7 !

      With 3/4 hour pedaling Sugar Boy was 3.3 and Fat Boy was 2.7

      How did they get Fat Boy up to 5.9 in the fasting test – I noticed his eyes were a bit black looking, maybe they got him to have a late night to facilitate their anti-science?


  9. Mike 30 January 2014 at 6:04 pm #

    I had seen something posted on another site earlier about this program. They quoted a nutritionist who was working with the twins saying that if people go too low carb that they can go into ketosis and the ketones can cause liver damage. That told more than enough about the bias of the people involved and gave it the credibility it deserves.

    Dr. MacKenzie, from what I have read that it is fructose, not glucose, that is deeply implicated in the development hepatic insulin resistance, fatty liver, and non-alcoholic liver disease.

  10. Jennie McGinlay 30 January 2014 at 6:08 pm #

    I was so annoyed by the programme that I wrote to the Radio Times, mainly because the low carb diet presented was, I thought, deliberately extreme – masses of protein/fat was stacked on the plate. I suspected they were just trying to sensationalize a supposedly “faddy” diet, to entertain at the expense of informing. To be fair, they did the same with the low fat diet – surely even the most enthusiastic advocate of low fat diets wouldn’t be recommending unlimited sucrose.
    I don’t think viewers would have learned anything – it was hardly a surprise that fat and sugar are delicious together!

  11. Norm 30 January 2014 at 6:47 pm #

    The way Dr Meckenzie approached the issue in the programme clearly makes me suggest him that he needs to improve his understanding A LOT of how insulin works in the body and the key role it plays in how other hormones work. He must know that what matters is how much insulin is being released to control blood glucose levels. It was obvious that high carb twin was releasing too much insulin. High fat twin would show a lot better insulin levels despite the fact that his glucose was a bit high because he was too much low on carb and in such a state insulin leaves the glucose for the brain to take up instead of shunting it to other cells. I really feel sorry for Dr Meckenzie’s patients if he has any. I was stunned at the sheer ignorance of both twins regarding nutrition and metabolism. The conclusion was that it is fat and sugar combined that makes us eat more whereas we did see that haigh carb twin had hardly any fat but was hungrier and ate more. No key markers of heart health were measured: CRP, TRIGLYCERIDES/HDL ratio, APO B etc where the high fat twin would have clearly won. Reaching the wrong conclusions with bad science is a massive problem with the mainstream health gurus. I have to agree with Dr Briffa that this documentary was really a tragedy.

  12. Dr John Briffa 30 January 2014 at 6:53 pm #


    Have you taken leave of your senses?! Dr Mackenzie has published in this area and is clearly beyond reproach.

  13. Kate Holland 30 January 2014 at 6:55 pm #

    I read enough about this beforehand that I didn’t bother to watch it. I’ve been low carb for over a year and am completely off my metformin and BP meds. My blood tests are perfect. I had been diagnosed as type 2 and followed the Diabetes UK guidelines and took metformin for 3-4 years.
    After reading this article and comments, I’m very glad I didn’t waste an hour of my life watching it! I have enough aggravation shouting at the Change for Life adverts!

  14. Dawn Waldron 30 January 2014 at 7:11 pm #

    A great analysis as usual Dr Briffa. There is more analysis and comment on this frustrating and damaging programme here. It’s a worry that the BBC can’t muster the resources to develop a rigorous small-scale diet trial.

  15. Greg 30 January 2014 at 7:17 pm #

    Agree, and to add to this, High Carb was Low in Fat and Protein. High Fat was low in Carbs, but high in Protein. only 2 subjects and only a month? I switched it off after couple of minutes.

    • Laura 4 February 2014 at 8:51 pm #

      YES! and High Fat didn’t show any vegetables whilst High Carb showed loads (including the Low Carb varieties!!!)

  16. Phil Woodrow 30 January 2014 at 7:21 pm #

    Horizon sugar v fat.This programme was as scientific as The House of Fools on bbc2 and not nearly as entertaining.They did try to entertain,but some doctors will never be Harry Hill.
    What they did do was make out that sugar is a healthy and essential product that our bodies need to survive.Fat on the other hand is still the killer it always has been.Especially TRANSfat which the high fat diet didn’t have,so why mention it then.?Not a mention of TRANSfat on the sugar diet where there would have been loads,considering most of the food was man made.
    To win the Tour de France all we need is,a good bike,porridge oats and sugar.Does that go for cricket as well,minus the bike of course.The poor doctor at risk of being prediabetic if he stayed on the high fat diet,should have a few words with a real expert Jimmy Moore.He was on a high fat diet for over a year wasn’t he? and still quite healthy I believe.The doctor on the sugar diet “On this diet I can still eat to shame” let him carry on that diet for six months and let us see if he is still smiling.

  17. Michael Allen 30 January 2014 at 7:44 pm #

    I thought in advance that this programme would be a complete waste of time, and would raise my blood pressure considerably, so thanks for demonstrating in two minutes flat that I don’t need to waste an hour watching the recording I made.

  18. John Read 30 January 2014 at 7:46 pm #

    John, I referred Amanda Ursell to the research contained in your books, after a press article she’d written. It seems that she might not have got round to reading them!

  19. David 30 January 2014 at 8:10 pm #

    Zoe Harcombe has pointed out that interestingly the twins did a documentary on channel 4 which was called “medicine men go wild “. Episode 3 of that series was a comparison of the traditional Inuit diet and the western diet. Apparently they came down very much in favour of the Inuit diet. Nothing like being consistent!

  20. Catherine Graham 30 January 2014 at 8:11 pm #

    I was so pleased to see your comments after I watched this programme (wish I hadnt)). I did not like how extreme they made the 2 diets, just for telly! I have followed your guidelines for over a year now, my life limiting IBS is a thing of the past, I sleep well, my weight is stable.

    I include green vegetables and berries, not cheese really, but yoghurt. I dont understand how a diet of jelly babies and meringues could be thought of as good which is the impression I got.

    Thank you for your sane words amongst so much madness!!

  21. Nads 30 January 2014 at 10:39 pm #

    Did it actually say how far thru the experiment the tests were done? Ie time to keto adapt?

    It is well known that a low carbers glucose tolerance test is not going to be good, unless they high carb it for a couple of days before. Also, physiological insulin resistance would explain the higher fasting blood sugar. It happens to me on fasting, yet my post pradial bg’s are great!

  22. Ted Hutchinson 30 January 2014 at 10:58 pm #

    Hannah Stutter has her say about How the TV bout Sugar vs. Fat was rigged at Health Insight.

  23. Steve Ward 30 January 2014 at 11:09 pm #

    Dr Mackenzie,

    As a type 2 diabetes sufferer, I would like you to respond to Dr Briffa’s comments re: clinical experience. I have followed the dietary advice that Dr. Briffa gives (in his book) and have been told by my endocrinologist that the various markers for disease have all improved in ways that other people do not usually manage without insulin and drugs (such as metformin).

    Also, is it not true that fluctuating blood sugar has been linked to inflammation, which in turn has been linked to a whole raft of other problems? Wouldn’t it have been better to measure hba1c and conduct an experiment over a longer period?

    Is it your contention that there are no studies that suggest that a high fat diet may in fact be safer than high carb? If those studies do exist, is it also your contention that those studies are less reliable than the 2 person, 1 month study in question?

    I am desperate to understand this as I am potentially facing a reduced life span and am struggling to reconcile how following conventional dietary wisdom was not as effective as following a low carb and fairly high fat diet. Indeed the only time I have seen almost normal blood sugar values has been to severely limit carbohydrate intake (despite advice to the contrary).

    Dr Briffa, perhaps we should do some fund raising for a study, given that most people struggle to follow arguments for themselves and generally seem to use a “top trumps” of status to determine who it believe.

    We really need to sort this out. My instincts, are that refined carbohydrates are the real killers (based on what I have been able to read and understand and what I have experienced for myself) but I feel that we need a way to try and settle this.

  24. Afifah 30 January 2014 at 11:25 pm #

    Hi John,
    Your analysis of this disgraceful programme was good, and I would like to suggest that anyone who has seen this travesty should stop paying their BBC license fee. They are clearly in breech of their remit of being informative, educational and entertaining. It was ill informed, counter enducational and not entertaining. If you pay by direct debit you can instruct your bank to stop paying them and take back any number of payments already made depending on where you place the date at which they broke their contract with you (to educate, inform and entertain). In my case I got back six months worth of payments and continue to be more than happy to have no tv. The bank cannot demand to know your reasons or challenge you. You will no longer be able to watch live tv but can watch
    the iPlayer when it suits you. This is what the Direct Debit guarantee is for. Use it.
    The point is, this programme, and lots of others like it, are being used specifically to misinform, obfuscate, confuse and, effectively, cause harm to those who have paid them not to. Goebbels would have recognised this sort of clever propaganda for what it was, i.e. an attempt to make people doubt the obvious truth that excess carbohydrates (all of them, starches and sugars) derrange the metabolism. Since we were all persuaded to reduce our fat intake for fear of heart disease, we have done so, and in the process have increased our carb intake. The effect has been obesity, diabetes, just as much heart disease, more cancer and a massive increase in dementias and neurodegenerative diseases, oh, and auto-immune diseases. Thanks a bunch.


    • Marc 2 February 2014 at 3:03 pm #

      If you watch using iplayer you are legally required to pay licence fee

      • Thomas Murphy 2 February 2014 at 3:58 pm #


        You’re not actually correct. The legal position is that you are only required to have a TV licence in the UK if you watch or record television programmes as they are being broadcast. It doesn’t matter what device you use to watch such programmes.

        If you only ever watch TV via catch-up services such as iPlayer and never watch them as they are being transmitted, you are under no legal obligation whatsoever to have a licence.

        In fact, the Daily Mail, amongst others, has carried a number of stories spelling out how worried the BBC is by this loophole. More than 400,000 people (including me) have not paid for a licence for years.

        See for one of the stories and see the official TV licensing website for proof that a licence is not needed if all you ever watch is catch-up services. That website can be found at:

        • marc 2 February 2014 at 4:49 pm #

          Thanks for that correction. I see you are right. Just morally wrong allowing others to pay for your tv programmes!

          • Thomas Murphy 2 February 2014 at 5:01 pm #


            Now that opens a whole can of worms! Given that the BBC long ago abandoned any pretence of impartiality or of adhering to its Charter to educate and inform; given its attempt to dominate the broadcast media by venturing into the commercial arena in every direction even whilst claiming still to be a public service broadcaster; given its extravagance and arrogance; given that it no longer produces programmes for intelligent viewers but only ever dumbed doqwn, over-existable and, in the case of its so-called ‘documentaries’ – given all that, I think it is the BBC that actually has a moral case to answer for blanket taxation of the TV watching public.

            As it happens, I watch very, very little TV anyway and none of it is BBC content because I can never find anything satisfying to watch. My conscience is clear!

          • Robert Park 2 February 2014 at 5:10 pm #

            Try not to allow your conscience to get in the way of achievement Marc, it sounds more like being intellectually brilliant! Just a pity that my age exempts me otherwise the temptation might prove too strong! Recall the recent incident in the news where an OAP took up shop-lifting as an avocation as she was bored doing nothing in her retirement. People do not like living in a vacuum; it does not matter what they believe even if it is immoral, illegal, or fattening, so long as it occupies and excites them.

  25. Carol Sayer 30 January 2014 at 11:56 pm #

    I just new it would be biased towards LCHF, and you just can’t argue with stupid, waste of time watching in my opinion.

    Thank you DR Briffa for your wise words.

  26. PhilT 31 January 2014 at 2:19 am #

    I would have found the programme more convincing if :-

    1. The twins had done a crossover onto the other diet, after a washout period in between. That way we would know if it was the diet or if one of them was just crap at cycling and thinking. As twins they may have the same DNA but they didn’t start at the same %fat, to name but one.

    2. The high fat guy had been fully in ketosis, the sharp eyed may have seen the ketone numbers on the flipchart in the cycling part where 0.5 is the highest number. I was at 0.7 watching it and I’m low carbing not zero carb – too much protein in his diet perhaps, or too early in his adaptation to ketosis. Either way the brain’s supply of ketones were constrained by the sub-optimal concentration in blood.

    3. They had taken advice from Volek or Phinney, or maybe Tim Noakes, rather than a carby CW dietitian (see her web site recommended breakfasts) and a carb obsessed cycle trainer. Each side of a comparison should have the right experts on their side.

    4. The BodPod technician had not referred to “muscle” but adhered to the scientifically correct “fat free mass”. A BodPod cannot determine muscle, only fat and other stuff. The “other stuff” will contain a fair bit of water in the high fat case, although he still lost more fat.

    5. The OGTT had been done after a 3 day carb rehab as is recommended for low carbers – see Hyperlipid etc. If you don’t eat any carbs for a month it isn’t a surprise that your carb handling mechanisms are half asleep.

    6. We had been given the full lipid results eg Total/HDL ratio etc.

  27. George Henderson 31 January 2014 at 2:58 am #

    Is there any way to shame them into making public all the test results, etc?

    Isn’t there some new law against hiding information from medical trials? Worth a try.

    To be fair, there is no reason why a metabolically healthy individual has to do better if they change to a diet radically different from the one they were adapted to. low carb diets are for people struggling with whatever they’re eating now.

  28. Neutral 31 January 2014 at 3:15 am #

    I feel your analysis is heavily in favour of high fat being the best diet, picking what is wrong as much as you can regarding defending this diet plan. I do agree this seems to side with “sugar is not that bad for you”

    what should be taken from programme is that neither a diet high in fat or sugar was largely beneficial to weight loss. I will try and give an opinion of someone who is fairly neutral towards diets in that they are not the key to maintaining a small frame or “lean” body.

    What I find highly interesting is that this analysis disregards what they says on 43 minutes, he indicates this experiment is definitely not scientific findings that can be relied on.

    What I find unbelievable is that the analysis did not highlight the main point at the end of the programme, recommendations from a lady who has studied data for the last 10 years, from 56m 30 seconds she states, stop eating processed food that contain high fat and sugar, by doing this and reducing the general calorie intake you will have a much larger chance to attain the frame you so desire from dieting alone.

    The doctors then go on to admit they were very wrong in what they had assumed to be true, they say high fat high sugar food is not good for you, they agree a very imbalanced diet is not good for your body. They say all diets are wrong, and doing exersize is the very important, please note “VERY IMPORTANT”


    If your a few stone over weight get up and exercise!
    maintain a set of muscles!
    consume less!

    (excluding lipodemia or any other body malfunctions)

    I exersize and i eat largely what i want, my size is lean because i excersie. NOT because i watch what i eat, If i ate more calories than i burnt off i put on some fat, If i drink a lot i get a beer belly. How can every person want to diet and have a body in healthy form.
    I work for my body not count calories.

    • mich 16 February 2014 at 12:41 am #

      Finally somebody with sense on here. Carbs are also very beneficial to us,however if you are sitting on your backside all day consuming carbohydrates,you are looking for bad health.perhaps you lose weight on low carb diets because you cut calories?

      • paulc 16 February 2014 at 7:57 am #

        No, we lose weight on low carb diets because we’re not producing so much insulin to handle the carbs. Insulin is the fat storage hormone and while you have large amounts of it present while dealing with carbs, it means the carbs get stored as fat and don’t come out of the fat cells because you still have high insulin levels.

  29. Dr John Briffa 31 January 2014 at 6:38 am #


    The points you make are all very good, I think. Thanks for making them.


  30. Dr John Briffa 31 January 2014 at 6:43 am #


    You have completely missed the point, which is this programme gave an impression from the ‘experiment’ that is, I think, misleading and not consistent with the wide body of relevant evidence.

    Your assertion that overweight people need to ‘move more’ and ‘consume less’ is also, I think, very misguided. The evidence does not really support these approaches for sustained fat loss, and neither do they seem to work to well ‘on the ground’.

    I’ve explored all this in my book Escape the Diet Trap. I don’t expect you to read it, Neutral, but the evidence is there, nonetheless.

  31. EVE ROBINSON 31 January 2014 at 8:02 am #

    No mention of thyoid problems causing obesity (underactive).

    • Lisa 16 February 2014 at 2:18 pm #


  32. Wilson 31 January 2014 at 9:03 am #

    The poor performance on OGTT taken by low carbers is called the Randle effect which allegedly normalises after 3-4 days of ‘normal’ carb eating. I have been curious about this and the programme seemed to support my experience. I am fit and thin but a year ago thought I’d give low carbing a go for general health and to lower a slightly high (5.5) fbg. I now notice that I have become extremely carb intolerant and despite introducing more in the way of rice, fruit, yogurt to eliminate the Randle effect I remain more carb intolerant than I was before going low carb. My food choices are more restricted now – has my body ‘forgotten’ how to deal with carbs altogether and how much harm are the high blood sugars seen after say having plain yogurt and fruit doing? Could it me that in my case (and studies only seem to focus on a certain physiology) a high carb diet has done me no favours at all?

  33. Phil Morse 31 January 2014 at 9:09 am #

    Thanks for debunking the high fat diet = borderline type 2 diabetes correlation, which did appear to be strange.

    What I took away from this, though, were two clear bits of common sense:

    1. Processed food high in fat and sugar somehow “overrides” the “no” mechanism, and is a prime driver of obesity. (That, and – in my view as a coeliac – any concentrated carbs, namely bread; try getting fat while avoiding bread, or better, wheat flour.)

    2. Use it or lose it – Resistance exercise is essential for muscle preservation. That was a timely reminder for me, as a 40+ who’s happy to run 3 times a week but finds it harder to motivate himself to do a little resistance training as regularly.

    Both of these items may have made some folk sit up and think, so maybe it wasn’t all bad. Maybe also I was immune to the bias, as a low carb (but not NO carb) diet has worked wonders for me. the programme certainly caused a lot of next-day chat among my friends.

  34. angela woolhouse 31 January 2014 at 9:10 am #

    I too was worried about the programs bias towards sugar. Even using the word sugar instead of glucose give the impression that eating loads of sweet sugary foods is ok. Fat was not given a fair hearing,no mention of the nutrients in the fat or even where good fats could be found. To me it said,eat as many sweets as you like but don’t eat butter or cream. Luckily I know better.

  35. Richard Parkes 31 January 2014 at 9:16 am #

    Dr Mackenzie, while I am glad that this programme was researched by an expert in diabetes, my concern is that I am pretty sure your twins were well aware of both the premise and the conclusions of the show before taking part in these “controlled” experiments. While I would have been happy to watch a programme that aimed to inform the public on the pros and cons of the fat vs sugar debate to present this as rigorous science is both misleading and dangerous and this is exactly what Dr Briffa has issues with. I am pretty sure there is now a significant number of people in the general public that will feel it is perfectly safe for them to keep drinking high sugar sodas, with no risk of developing diabetes as a result. I personally would not want that to be the legacy left by a piece of work I had contributed to.

  36. Bartypit 31 January 2014 at 9:20 am #

    For those who are interested, Sam Feltham has been doing a one man experiment , eating 5000 calories of , firstly, HFLC, then standard High Carb junk , and now a supposedly non junk vegan diet. He has already debunked the calorie formula.
    Zoe. Harcombe has always talked sense, and has an amazing scientific knowledge, and can back up all of her ideas.
    I note with interest that Dr Mckenzie has not replied to the legitimate questions posed here. I think he may be experiencing the phenomenon of us enthusiastic amateurs who are now informed, able to do their own research, and see through the bullshit of ‘scientists’ who have always been able to hide behind their status and present whatever bias suits. ( not all, but definitely some)
    I have learnt one thing since I started eating real food and ditching processed carbs two years ago, that the establishment , for some reason, is in denial and lies. I suspect Big Pharma and Big Business.

  37. Simon Shorrock 31 January 2014 at 9:23 am #

    What really annoyed me about this programme was that Mr ‘High Fat’ was essentially doing Atkins phase 1. I and many others who enjoy a Paleo lifestyle include non-starchy vegetables and a little low GI fruit. Nobody would recommend this diet for the long term unless vegetables and fruit were sparse. My feeling is that the programme had an anti-Paleo and anti-fat agenda. A far better insight into the effects of a high fat low carb diet would be too watch the recently released documentary ‘Cereal Killers’.

  38. Alicia 31 January 2014 at 9:28 am #

    I have to say that I cannot believe the levels of on animosity on this site. It was, at the end of the day, a TV programme and surely no better or worse than the hundreds of other supposedly accurate science or weight loss programmes that populate the schedules?

    All of us who watched or who turned off started with our own preconceptions and we all expected to be proved right or wrong dependant on our standpoint – the fact that most of the comments here are so judgemental appears to prove my suppostion right although I have absolutley no doubt that I will now encounter a huge amount of negative comments for having an opinion!

    For the record my view has been for some time that high carb is a bad thing (and I would suspect that most people who subscribe to Dr Briffa) do so because it is a view they share) but I am perfectly capable of watching/reading other views. I would point out that it is patently unfair to dismiss the scientific views put forward and to criticise what they said or didnt say – it was a TV programme and the producers/editors are the ones to determine what makes the final cut NOT the scientist who contributed.

    And please, it really is beneath you Dr Briffa to take cheap shots at Dr McKenzie and anyone else who doesnt agree with you.

  39. John B 31 January 2014 at 9:28 am #

    I avoided this pseudo-science reality TV because, from past experience, such programmes are made with a bias to confirm.

    And right on cue, as far as I see from Dr Briffa account, we have a doctor with a bias to confirm; there was no control, or testing of the twins on their usual diets; it was not conducted blind; subjects selected according to what criteria apart from identicial twins?

    Sadly, just like what passes for most ‘science’ these days in the area of health, and of course climate, the results lust be valid because I, clever ‘scientist’ with ‘peer reviewed’ papers published say so and others in my clique agree with me.

    You fight the good fight Dr B in challenging these humbugs.

  40. Dr John Briffa 31 January 2014 at 9:40 am #


    “It was, at the end of the day, a TV programme and surely no better or worse than the hundreds of other supposedly accurate science or weight loss programmes that populate the schedules?”

    Does that mean, somehow, that all potentially damaging misinformation should get a free pass and be let go with a resigned shrug?

    “it really is beneath you Dr Briffa to take cheap shots at Dr McKenzie [sic] and anyone else who doesnt [sic] agree with you.”

    What, in what I have written, constitutes a ‘cheap shot’, do you think? I felt I raised some legitimate issues which, as yet, Dr Mackenzie has not engaged with in any meaningful way. He, on the other hand, seems more stuck on the fact that he is a published in the area, and that I am not. Not the best defence on one’s views, I’d say…

  41. Kate 31 January 2014 at 9:46 am #

    The Sugar vs Fat Programme was just that – a piece of television. The main function of this genre is entertainment. I would not expect complete historical accuracy from, say, a Hollywood film about the American Civil War. If I want accuracy, I would have to research the topic myself using learned sources and even then, I would not necessarily find that sources agree.

    It could be argued that as television is a powerful medium, it has a duty to inform in a balanced way, using at the very least up-to-date published and properly conducted scientific research. But mainstream TV channel programme makers are like the popular press – their function is to sell newspapers! Stirring up controversy probably boosts the ratings and the programme should be viewed in this light alone.

    I would no more expect valid information from this genre as

  42. Jules 31 January 2014 at 9:58 am #

    I too found the programme irritating and agree with the majority of comments already posted. However, what I found most concerning was the implication that a high carb diet ( with lots of pictures of sugar lumps) was going to do you NO harm. I think if I were so inclined, I would come to the conclusion that I could eat sugary cereals, chips and crumpets without any adverse effects, and still lose weight! I imagine many people will breathe a sigh of relief and settle back on the sofa with a bag of crisps and a doughnut.

  43. Marc 31 January 2014 at 10:13 am #

    I haven’t seen the show because I live abroad, but here’s what I can say: having followed Dr Briffa low carb diet, I have lost 13 kgs and am in great shape.

    More importantly, one of my Russian friend suffers form Type II diabetes: he started following Dr Briffa’s recommendations 4 months ago. He lost 7 kgs only, but for the first time in 8 years his blood sugar level went under the level when you are considered a diabetic. He had blood tests when he started the diet, and another one mid-January: everything is normal and his MD said it was an incredible result.

    - His wife lost 9 kgs without any hunger. She says she feel awesome.
    - My sister lost 5 kgs and she told me yesterday she is in the greatest shape ever.

    I know it is purely anecdotal and no science at all, but no more than these twins apparently. As for myself, I eat what I want I don’t gain weight and I feel good.

    More importantly, if everything Dr Mackenzie tells us is true, how come obesity is becoming epidemic nearly everywhere ?

    It’s quite interesting to see the rhetoric behind his post here. Mackenzie is using argumentum ab auctoritate, but as Dr Briffa pointed out, the appeal to authority is a common logical fallacy because authorities are not necessarily correct about judgments related to their field of expertise. Then he tries to ridicule Dr Briffa for writing his opinion on his blog, and expresses doubts because Dr Briffa is selling a book.

    It would be interesting to know if Mackenzie received any kind of compensation for this TV show ? If he did his argument above is pointless, if he did not then he was doing a poor service to science just to prove his point.

  44. Sue Gooch 31 January 2014 at 10:13 am #

    I didn’t watch the programme, the quote from one of the twins in the press beforehand was enough to put me off,

    “But here’s the problem: despite being doctors – I also have a degree in public health – neither of us knew much about losing weight and eating ”

    What an admission in a world with obesity overload!

    Neutral, you seem typical of someone who feels qualified to comment on obesity without ever having been fat and therefore never having had to dig much deeper into the “eat less, exercise more” fallacy that I can tell you doesn’t work.

    There are many websites and weight loss “experts” out there: while years ago most of these would have been of the “you must count calories and avoid fat like the plague” variety, they are fast becoming outnumbered by the eat low carb, higher fat sites which carry many testimonials that this approach has improved not just the weight but the health issues, the fitness and just as importantly, the sleep.

    My favourite of the moment is that of Dr. Jack Kruse, an American neurosurgeon, who needed to deal with his own weight problem and did so by taking a very in depth look not just at nutrition but at the bio-chemistry involved. Whilst I’m not a huge fan of his style of presentation, he seems to have gone down many roads, looked at a lot of diverse research and concluded that fat is in fact the most necessary nutrient for optimal health. Not any fat though but animal fats, found in grass fed meats and non-farmed fish. So much appears to take place at micro cellular level that the old equation of move more eat less is shown to be truly outdated. His research into leptin has convinced me that he’s closer to unravelling the mystery of obesity as anyone else I’ve read about.

    The programme appears to have been a bowlful of nonsense served up to a gullible public, it has set the course of nutrition back for years. I’d be interested to know who funds Dr. Mackenzie’s research and who had the idea for the programme? That may shed some light on the content and outcomes.

  45. Ricardo 31 January 2014 at 10:15 am #

    The only mistake made by the BBC was that they should have screened it on the 1st of April.

  46. kevino 31 January 2014 at 10:22 am #

    An earlier poster mentioned Prof. Tim Noakes (one of the world’s foremost sports scientists, trained as an MD and a ‘convert’ to LCHF/Banting). I got the following very intersting link from him. It leads to a very interesting (and unsually balanced) examination of the relative merits of LCHF & carb loading for cyclists. A pity that the cycling expert on the show was apparently unaware of this.

    • Ed 3 February 2014 at 12:13 pm #

      Two things :

      1) if you look at the proportion of carb usage as you ramp up the intensity, you’ll see it reaches 100%. If you’ve experienced hill time-trials / climbs during races, you’ll know that you are working at well above your functional threshold power level. In the programme, this was a race, not a gentle bimble. Therefore, they’ll be at VO2 max and relying on 100% carbs. Unless there is some specific knowledge you have about high intensity activity like that which contradicts the article you refer to?

      2) the quote at the end of the article from Joe Friel –

      “Eating a LCHF [low-carb, high-fat] diet has not directly improved my performance. I’m not faster now than I was before. This is common in the research I’ve read on the topic. What it has improved is getting to and staying at race weight without calorie counting or hunger.”

      I’d say that supports the position of the Team Sky coach.

      • David 26 March 2014 at 12:19 am #

        These cyclists had already cycled some distance before the uphill race but fat-boy was held back when I would have expected him to have the advantage in endurance. No surprise that sugar-boy was faster in an uphill sprint.

        So train on low carb and stock up on race day.

  47. bob 31 January 2014 at 10:23 am #

    I wouldn’t make too much of the fairground setting of the Lustig interview. He has been interviewed there before, and probably chose it because it’s close to his workand/or is somewhere where you’re surrounded by sugar.

    The programme’s false division of the UK (fat is bad) and the US (sugar is bad) was odd and unnecessary. Far as I know, both country’s official bodies encourage carb-rich diets…

    • Laura 4 February 2014 at 9:05 pm #

      Oh YES! This was another bizarre anomily I registered, as I was watching!

  48. Caroline 31 January 2014 at 10:24 am #

    I watched the Horizon programme and I feel it was irresponsible broadcasting, leaving the public feeling very confused. It was presented in a style deliberately intended to alarm its viewers without actually giving proper information. Us viewers didn’t ever get to know what it was the twins were eating precisely. Is there a detailed list of what they ate? Did Dr Low Carb eat vegetables and berries because one would normally eat a lot of these on a low carb diet? Broccoli, watercress, aubergines (etc), contain fewer carbs most sausages (I noted he was eating sausages). Why didn’t he eat Melanzane Parmigiana accompanied by a big rocket salad with parmesan shavings and a herby olive oil dressing?

    So if anyone involved in the programme would please be kind enough to publish the precise diet I would be very grateful.

    The programme is probably responsible for lots of people abandoning low carb diets, even though Dr Low Carb was probably NOT eating what’s widely recognised as a sensible low carb diet.

  49. Mrs Christine Margaret Simmons 31 January 2014 at 10:51 am #

    I absolutely agree with every word of Dr Briffa on this issue, and my own personal experience confirms it.

    I’m a bit puzzled by Dr Mackenzie’s introductory remarks. He sounds a little nettled (and defensive?) when he personalises the issue: “You write very interestingly. I assume this is for impact to ensure people read your work?”

    Umm, isn’t that what all good writers – of articles, novels, essays, letters – do?

  50. Jools W 31 January 2014 at 11:07 am #

    I did not watch this program as I knew it would be biased in favour of a high carb diet; my husband said he wouldn’t stay in the same room if I did watch it, as I would end up shouting at the tv!

    I changed my eating habits 8 months ago, and cut down drastically on eating sugar and carbohydrate laden foods. I’ve lost 2 stone and never feel hungry. I suffered from IBS and it seems to have gone. I feel well. Everyone tells me (unprompted) that I look “great”.

    Enough said. I’m carrying on as I am.

  51. Thomas Murphy 31 January 2014 at 11:31 am #

    The programme sounds like a load of rubbish to me. I was diagnosed as a Type 2 diabetic three years ago. I was on insulin for about seven months and have been on high doses of Metformin ever since.

    My partner and I have read your book and also been investigating the Paleo diet. Despite following standard hospital advice, I have struggled to control my blood sugars – which is how we came to know of you.

    We tried the Paleo diet – not very convincingly, if I’m honest – and noticed that, even though we were not adhering to it properly, we felt better in ourselves and were eating less. We also discovered that we rapidly lost our taste for sweet things and processed foods, of which we now eat virtually none.

    This year, we resolved to do the thing properly and – lo! – we have both started to lose weight, something which has eluded us over the last three years.

    I also noticed that my blood sugars were much better controlled than they have been – to the extent that I did not always need to take Metformin with every meal. Last Sunday, as an experiment, I decided to see what would happen if I took no Metformin at all whilst eating a Paleo diet and virtually no carbs (except for salad vegetables and the occasional roast sweet potato).

    The result? I haven’t taken a Metformin since Sunday night (26th. January) and my sugar control has been consistently BETTER than normal. Without any medication whatsoever, I have been recording sugar levels in the high fives and low sixes consistently throughout the day. Earlier this week, I recorded 4.4 mmol/l, something which left me feeling light-headed and shaky. That feeling, by the way, is one I last experienced when my sugars were being brought down from the high twenties to the low teens!

    Confession time: last night, I had a large glass of pear and cardomon juice. It’s delicious but not good for my sugars! But her’s the thing: once ypon a time, that would have sent my sugars soaring well into the mid to high teens. Last night, they only went up to 10.5 mmol / l and, more importantly, they came down again before bedtime and only increased by 0.3 through the night. We’re talking about someone who normally experiences a night time rise of 3.0 mmol / l. This morning, my sugars are still elevated slightly – but they are below 10 and that is still without having taking any medication whatsoever for five days.

    I’m not a doctor and I freely admit that different people are made differently. From my own experience, however, carbohydrates are largely unnecessary and, increasingly, I don’t enjoy most of them. I am now seriously considering for the first time whether I can manage my diabetes long term without medication – just by controlling my diet and abandoning the “low fat / carbs” orthodoxy. Obviously things like stress and exercise come into play as well – but the biggest single change to situation has been the change in diet.

    By the way – it’s true about protein calories being more fulfilling than carbohydrate ones. Now that I have got into the swing of this new way of eating, I am consuming anywhere between 1,100 and 1,500 calories and not feeling particularly hungry until dinnertime.

  52. Dr John Briffa 31 January 2014 at 11:33 am #

    Mrs Christine Margaret Simmons

    I was also a bit puzzled by Dr Mackenzie’s opening remarks, and I think (but don’t know) they were an attempt to suggest that I put style over substance.

    I’m very eager for Dr Mackenzie to answer the questions he has posed here. I’ll be happy, personally, for him to dispense with style as long as he provides plenty of substance.

    I’ve emailed him to encourage him back to the debate.

  53. Tim 31 January 2014 at 11:34 am #

    We have been told that eating saturated fats WILL raise cholesterol levels and will increase the chance of a heart attack . When the twins cholesterol levels were checked at the end of the trial they were pretty much at the same levels as when they started the diets .You would have thought that this would have been pretty shocking to those who believe in the lipid hypothesis for cardiac arrest ( i.e. the majority of the medical establishment), and yet it was pretty much glossed over.

  54. PhilT 31 January 2014 at 11:38 am #

    @Neutral regarding “recommendations from a lady who has studied data for the last 10 years” that would be Susan Jebb who in 1995 co-authored a paper which concluded…

    ” average recorded energy intake in Britain has declined substantially as obesity rates have escalated ” – so her own work fails to back up the notion that “it’s all about the calories, stupid”.

  55. Edward Taylor 31 January 2014 at 11:43 am #

    If high fat had been allowed low-sugar fibre (veggies) the show would have been hailed a miracle in health and weight-loss. As it is the millions who watched the show will take away from the program that High-Fat is dangerous, High-Sugar will make them perform better (mentally and physically) and they should avoid ice-cream or sugar coated doughnuts without any mention that the deadly 50/50 combination of fat and sugar exists in so much of the average British diet (rice and curry, pasta and meat sauce, cottage pie, sandwiches and breakfast cereals etc..) How helpful was it deplete glycogen and then race up a hill fat v sugar – who does that benefit??

    • Laura 4 February 2014 at 9:11 pm #

      YES! YES! YES! I’m beginning to sound like Sally in that famous film but I’m so relieved to read that other people were summising the same things as me as they watched this programme. I had a terrible 24 hours after watching it, overly anxious that I had somehow done myself irreprable harm by adopting a LFHC diet 2 years ago even though I lost 4 stone and have never felt better after living miserably fat and hungry on a low fat diet for nearly 20 years. I admire and respect the BBC and would never ever have a go at the whole institution for the broadcast of this one show but I have to agree, the irresponsibly presented and inaccurate information contained therein should be debunked publicly for the sake of the health of the country and the sanity of anyone like me!

  56. Jennifer 31 January 2014 at 11:50 am #

    I am elated with the responses that your blog is attracting re a LCHF eating regime, considering the thrashing it seemed to get on that dozey Horizon programme. As I said yesterday, the conclusions initially alarmed me….but the proof of the pudding is out there..judging by the stories being reported here.
    I have no intention of eating carb rich food ever again….I am more than convinced that carbs are not essential, althogh I concede, LOW carb is the norm for me, and certainly not NO carb, which is almost impossibel to achieve, and not even necessary in order to achieve optimum health benefits.
    Off to make my liver and onions, followed by home made Greek yogurt and 20g raspberries. I.e. Quality protein, animal fat and a few carbs to add interest.
    Fibre? Poo…I .don’t give it a thought these days…..low carb does NOT cause constipation. And as for bad breath…..we all fast overnight, and generally can’t wait to brush our teeth 1st thing. What’s the problem?

  57. Dawn Waldron 31 January 2014 at 12:06 pm #

    Perhaps the biggest irony of the whole debate is that they weren’t actually testing high carb vs high fat because the US twin’s diet was so badly designed that it was, in effect, a high protein diet. Sufficient to hamper lipolysis and ketosis and render any results totally meaningless. What a waste of BBC budget!

  58. Chris Young 31 January 2014 at 12:09 pm #

    One massive are that wasn’t even touched on was how important our gut biome is. It is highly likely that the twins have very different bacterial colonies and therefore there response to food would be very different even if they were on the same diet.

    Then you have quality of sleep and exercise (high intensity weight training would have put a stop to that muscle loss). Neither of those were mentioned either!

    Oh and how about the source of the food – grass fed?

  59. John Walker 31 January 2014 at 12:19 pm #

    To Neutral,

    I have lost three stones (42lbs – app 20 kilos) in fourteen months, by following most of Dr. Briffa’s recommendations. I agree with where processed food is concerned, but dispute that it is the ‘high-fat’ that is the problem; also that it is simply the combination of sugar and fat combined that makes such foods palatable. I believe that sugar is addictive, and therein lies the problem. The lady professor, I have seen two or three times on TV, extolling the virtues of low-fat, whole-grains, high fibre and serious, gym-style exercise. I think she is hidebound by ‘conventional wisdom’, So regardless of her qualifications, and her experience, I can’t take her seriously.

    Why don’t you try a month’s experiment? Cut out bread and other starchy foods. You can get ample carbs from fresh, green vegetables and fruit. (Easy on the fructose though) Take a brisk walk every day. Also indulge in some activity that pushes you for short periods; such as gardening, hand-woodworking. Anything that requires you to use energy. Why waste valuable time, huffing and puffing around the streets, oblivious to all that is going on around you, and obsessed with the idea that you are burning off calories? You might be, but you are also wearing out your hips and knees, and you will find out, as did I, that the game isn’t worth the candle. I just wish I’d heeded Dr. Atkins advice in the 1970/80s! I might still have my own knees, instead of titanium and plastic joints! They are adequate, and I am grateful to be free of pain, but I’d sooner have bone and gristle, thank you. As to fat versus carbs, to my mind, as long as you are sure of a beef-burger’s origins and ingredients, it isn’t the meat that does the damage but the bun.

  60. SueG 31 January 2014 at 12:19 pm #

    Just a small addition to the debate. My husband and I are both several stones overweight and gave up carbs nearly two years ago.(he’s a type ll). Initially we both lost weight. Since then we have both yo-yoed up and down with the most weight loss following the 5:2 fasting style, still sticking to low carb.

    Since then we watched Dr. Lustig’s video and decided that sugar/sweetened food had to go too. I’ve kicked it completely, he still has the odd cake and we both have porridge about once a week. I’ve done this now for over a month, I still haven’t lost any weight over and above the 7lbs that remains of the no carb weight loss. We’re both reasonably active, we spend an hour a day walking the dog.

    My husband is despondent although he isn’t quite so good at avoiding carbs (he has water biscuits with cheese on a Sunday after dinner), now he thinks he shouldn’t eat an English style breakfast because he thinks it’s too much! I have taken to eating more fat in the form of coconut oil and raw butter, I haven’t put any weight on but neither is it coming off. We eat only 2 meals a day, we don’t have huge portions because I prefer quality over quantity. So if Neutral was right, we should be slim as anything, we aren’t. I personally feel better, more energy and motivation but I still feel there is a missing link, possibly the Leptin resistance theory favoured by Dr. Kruse.

    I don’t lust after carbs at all and more surprisingly, sugar. Very little of our food comes out of tins or packets, we cook from scratch and invest time in making our own stock from bones etc. It’s really not a straightforward eat less move more equation.

    One thing we won’t be doing is slipping back into just eating anything we fancy, that way lies certain failure for any sort of a healthy life.

  61. Sue 31 January 2014 at 12:20 pm #

    Once controlled underactive thyroid does not cause obesity.

  62. Bodil Mjoelkalid 31 January 2014 at 12:54 pm #

    It is scary to have displayed with no shame how little standard medical doctors know about insulin and diabetes. And God help us, they treat it!! The researcher displayed the same lack of knowledge. If I cannot get my patients on to a low carb, high vegetables/protein/fat with all meals, they will not get well.
    A pre-diabetic situation was diagnosed by doing sugar tolerance test and measuring blood sugar only, on somebody whose insulin was low because he has had no or little carbs for a month. Long term sugar-effect, HbA1c, would have given a totally different result; high for sugar-twin, low for fat-twin! HbA1c and Insulin should be used, not blood glucose.
    Insulin is anabolic. You will not build muscles without insulin. Sugar-twin lost 50% of muscle mass in his weight-loss (only 1 kg). Fat-twin lost 62% of muscle mass in his 4 kg weight loss. I am amazed the difference was not higher considering there was not much insulin being produced.
    Only short term effect of sugar/ fat for energy was measured. Up on hill, and sugar won. Of course! Sugar is for short spurts of energy. Fat is used for stable long-term energy. Go for a long run on sugar and carbs only, and you will have to use sugar all the way round. Go for a run on a mixture of carbs and fat, and you will last!

    The sad fact is that this program will now have the less informed think that sugar and carbs are better than fat, esp. saturated – heading for type II diabetes.

    When will journalists and producers start feeling responsible for the way they make money?
    To me, the “information” or lack of such, in this program is potentially suable.

  63. Brian Fullerton 31 January 2014 at 1:16 pm #

    Lets see now fat and sugar combined are very addictive….Shock never saw that one coming (LOVVL)

    The question is which of the two is the bad guy ?

    Fat:- Eaten from (and before) homo-sapiens inception 2 or 3 million years!!
    Produces satiety and is full of soluble vitamins and nutrients.

    Refined Sugar (and other starch [sugar] rich foods i.e grains):- eaten as a staple only in the last 10 to 12 thousand years (along with the introduction of diseases of civilization)!!
    Produces almost instant high blood sugar with a resultant spike in insulin to compensate followed by a blood sugar crash and ravenous hunger for more carbs and has ZERO nutritional value.

    Such a difficult one (unless I’m a giant “food” processing company)

    Staying with common sense gene for a mo
    Q. If I was to enter a up hill bike race would I choose to eat:-
    A: an almost instantly utilizable glucose jell “drink”
    B: a small piece of (disgusting on its own) butter fat that will take probably a couple of hours to fully digest.

    Go figure

  64. Amanda Smith 31 January 2014 at 1:24 pm #

    It depresses me that so many people will have viewed this with interest and extrapolated what has been said as fact. There is such an enormous amount of mis information out already about ‘diet’ surely the BBC have a greater duty of care to ensure what is put out as a serious documentary has a truthful message. Or at the very least one that isn’t so biased from the off.

    Excellent write up from Mr Substance!

  65. SueG 31 January 2014 at 1:53 pm #

    Well, if you thought that was dodgy research and poor summation, try this from today’s Daily Mail:

    Words fail me!

  66. Gary 31 January 2014 at 2:16 pm #

    I doubt Dr Mackenzie has the balls to rejoin the debate, I think the point of the programme was to stifle debate and support the status quo of the existing paradigm of ‘lack of self control’ causes obesity and saturated fat causes heart disease, he’ll probably hide behind the university walls and the TV camera and refuse to enter into a discussion of scientific evidence in public, this is the nature of dogma, his work is finished.

  67. Rosie 31 January 2014 at 2:41 pm #

    Please please Dr Briffa keep up the good work for the ordinary people (Joe public) who need you to keep them informed. Thank you very very much

  68. Colin Hardie 31 January 2014 at 2:43 pm #

    They should have just shown Fat Head instead. Does a much better job of explaining the ‘science’ going on for the ‘typical viewer’. Expected more from Horizon to be quite honest!

  69. paulc 31 January 2014 at 2:43 pm #

    Any Glucose Tolerance test result is ONLY valid if you have been eating at least 130 grams of carbs per day in the three days immediately beforehand. To inflict an OGTT on someone who is not eating carbs at all is pointless and makes the result invalid.

    Also the protocol requires a blood glucose check using a meter and test strip immediately before administering the glucose load. If the reading at that test is 11 mmol/l, then the OGTT is to be abandoned as the patient is clearly already diabetic. Was this done beforehand?

    The entire exercise by this program appears to have been devised exclusively to demonise the high-fat diet as dangerous.

  70. bob 31 January 2014 at 2:45 pm #

    So, to get bigger muscles, you need carbs? Or protein in sufficient amounts, in order to get an insulin response?

  71. Neutral 31 January 2014 at 3:30 pm #

    I agree refined sugar is not a great benifit to our health, but I will also say sugars from natural sources are NOT the cause to obesity, you eat more than you burn off you get fat, the basic the most obvious solution is more often than not true,

    everyone is making money out of diet fads, get up and burn off calories.

    Howcome you never see overweight sports people? they play sports they dont get fat and they eat what they want. The point of the show was reducing overweight people. not the inner damage you are doing from eating sugar.

    A balanced diet is what you need, and not too much sugar or fat from cheesecake and ice cream. you exersize and your body works like a clock….. why are you all bias towards high fat diets.. you take from the show it was slightly bias and not the MAIN POINT

    eat less cakes, be fit, exersize and you wont have a big belly….

  72. Jonathan Bagley 31 January 2014 at 3:39 pm #

    I was disappointed that the two diets chosen were so extreme. I was expecting a low carbohydrate diet with plenty of fat, but including, for example, carrots, salads and green vegetables; and a high carb (normal UK) diet including lots of bread and pasta. I just cut down on bread and potatoes a little, cut out biscuits and ate more eggs, cheese and nuts, losing 2 to 3 inches from my waist. This is what Fat vs Sugar brings to mind with most potential viewers – not one person living off meat, cream and lard and the other not touching fat at all.
    The brain test was a joke. There are plenty of standard psychological tests available. Don’t patronise us. Same for the cycling test. They should have been wired and tubed up on a stationary cycle, testing change in fitness, from their pre dietary states. Also, this fixation on “processed food” annoys me. These people should look up a few cake recipes. Homemade cakes are little different to the doughnuts. Victoria sponge, butter and sugar in equal measure. Have a go at the BBC baking programmes for a change.

  73. Neutral 31 January 2014 at 3:45 pm #

    To john walker:

    your joints may be worn out due to your size and body frame not being capable to withstand the additional weight. I play tennis and my job is a gardener, I will never be overweight unless i stop being active.

    congratulations on your weight loss however sugar in its natural form is not addictive, sugar cane is refined sugar and readily available, I am not addicted to apples which contain high amounts of sugar, so your point is majorly flawed. sugar is addictive because it is a high source of enegy, how would you expect to burst out energy without sugar ??? IE honey…. natural sugar is not bad for you…..

    The information from the lady doctor was based on findings from scientific experiments over the past ten years, she was very fair in what she said and highlighted the commonly known problems of obeseity, she said reduce your calorie intake and you will loose weight, dont eat cakes, and I find it very entertaining you claim you cannot trust this information.

    Why would i need to try out a diet if I am not overweight???? I do not want to lose weight i want to gain muscle mass thanks…

  74. Dr John Briffa 31 January 2014 at 3:47 pm #


    “everyone is making money out of diet fads, get up and burn off calories.”

    Have you looked at the research into the impact of exercise on fat loss? If you have, you’ll know just how ineffective it tends to be. If you haven’t, then your opinion is just that – an opinion (and an uninformed one at that).

    “Howcome [sic] you never see overweight sports people?”

    You’re making the assumption that exercise leads to weight loss. It fits with your bias, but how about the idea that people are more likely to athletes if they are naturally thin?

    Plus, the idea that overweight sportspeople do not exist is utter fallacy. Watch the rugby union internationals at the weekend and look for players wearing 1 or 3 on their back to see very fit and strong men running around while likely carrying around body fat that might be classified as ‘overweight’ or ‘unhealthy’.

  75. Thomas Murphy 31 January 2014 at 3:54 pm #


    Life seems so simple for you!

    My partner has very low iron levels and has to supplement simply to bump along the bottom of the scale. In no sense can she be called a glutton and she exercises every day – yet she struggles with her weight. You name the diet and she’s tried it. Most of them haev been variations of low fat, high carb “healthy” diets. They have left her lethargic and constantly hungry without ever meeting her real nutritional needs.

    Two things happened which are beginning to turn things around. The first was that a friend recommended she move off the iron ferrosulphates on to iron glycinate; the second was that we read Dr. Briffra’s book and started learning more about how the realtionship between food and weight is about so much more than your, if I may so, highly simplistic and simply wrong mantra “eat less, move more”.

    As to your point about sports people, my understanding is that they DON’T eat what they want. They eat very specialised diets to help them to perform at their best within their chosen discipline. The ones who need speed eat differently from the ones who need strength.

  76. PhilT 31 January 2014 at 4:01 pm #

    @Neutral “Howcome you never see overweight sports people?” – you do, if you look. Several members of the Australian cricket team were overweight and adopted a low carb high fat diet to address it – see

  77. Jennifer 31 January 2014 at 4:37 pm #

    In response to all those doubting the physiological processes of food digestion.
    If global calorie consumption has reduced….simply look at the calories in a gram of sugar, compared to those in a gram of fat….approx 2:1.
    This would account for a total calorific reduction if sugar replaces the fat….as has been pushed at us for the last 40 years..
    But those calories of SUGAR are laid down as FAT, causing metabolic problems. I don’t count calories…they are a red herring…I count grams of non-essential carbs from all sources…because the majority turn to glucose after digestion, and our systems are unable to cope with a high volume of glucose continually bombarding them. Excess fruit sugars damage our livers, in a similar way to excessive alcohol. Dietary fat is metabolised in a different way, and our body systems have evolved to cope with this essential macro nutrient.
    Until this message gets understood and accepted…..I pray that these blogs will keep going….but some people will just not learn.

  78. Pete Grist 31 January 2014 at 4:42 pm #

    I didn’t watch the programme as it looked far too gimmicky. But it would seem to indicate the beginnings of a shift from fat is the evil one to sugar taking on that role (not before time). However a lot of medical opinion is still in the fat camp, and the BBC is mainly going to reflect the mainstream, though I do detect a gradual increase in alternative views, particularly on the radio.

    I’m not surprised that the doctor has not replied as he clearly is not going to be believed. I enjoy Dr Briffa’s posts almost as much as a fresh slice of good bread (evil) with butter (good?).

  79. Mat 31 January 2014 at 4:44 pm #


    I’ve been playing basketball now for 5 years… I haven’t grown an inch..

    It is so frustrating to see all these really tall basketball players.. Playing basketball *must* make you grow taller as all basketball players seem to be tall…

    Or is it that you generally only see slim athletes because generally slim people go into athletics..

    I think they call this the difference between association and causation – You’d do well to look it up!!

  80. Anthony Graham 31 January 2014 at 4:59 pm #

    Is there any reason why their physical and mental skills should be comparable? Is being fit 100% hereditary and indeed is intelligence? The programme also failed to mention that NY twin’s weight once ballooned to 17.5 stone…. the UK twin’s did not… They may be identical in DNA terms but that is only part of what makes a human.
    Thought the programme was shallow, bad science, dangerous and misleading.

  81. Robert Park 31 January 2014 at 5:00 pm #

    Tell me the old, old story! Biased, poor science, propaganda, was the resounding tinkle that came across from this tv programme. What was appalling was the disgusting eating habits of those twin doctors.

    I subscribe to Sue Gooch’s view (above) on the benefits of saturated fats. When plaque was analysed it was found to contain a massive 70% made from PUFAs, 23% from saturated fats, and 7% from other sources. When it is considered that saturated fat also contains in its structure both poly and mono unsaturated fats it can be reasonably deduced that saturation by itself is not the problem.

    When organ transplant surgeons were searching for an effective immune suppressant the most potent substance found was vegetable oil (need more be said)!

    Monounsaturated fat (olive oil) requires to be kept in dark containers to slow its deterioration which when it enters the body creates masses of those nasty wee free radicals (the science is out there) which are harmful at the cellular level to the body.

    Bacon, these days, often has water pumped into it and what does this create? It creates transfat which, as is recognised, is harmful; the same applies to whipped cream but the science has not yet caught up with the obvious.

    Traditional Inuits lived on a diet which principally consisted of PUFAs and were relatively free of cardiac problems but they looked older than those on a Western type diet and failed to live longer so what caused those problems? Their deaths were due to aneurysms caused by thin arterial walls. When injured, bleeding to death was common owing to their thin blood.

    When Captain Scott was preparing for the Antarctic expedition he took the advice of the best medical authorities (big mistake) and ignored the experiences of other Arctic explorers. He was advised not to add fat to the pemmican. This lack of fat was probably what brought about the demise of his team yet we British seek to make a folk hero out of a failure.

    Saturated fat creates cholesterol which creates those essential hormones which maintains health and gives the feel-good factor to our lives so why reduce it? Even LDL has beneficial effects otherwise why would the body require it? My own experience since the 1950s (unscientific) is that lashing of saturated fat in the diet is a buffer to ill-health.

    Currently, my interest is in the effect of glucose as it appears to be the only sugar substance from which all organs of the body utilise and seem to benefit.

    Finally, the twin that was on the low-carb diet complained twice of feeling unwell and it would therefore have been interesting to know the breakdown of the fats he consumed.

  82. Dan L 31 January 2014 at 5:57 pm #

    Watching the second half only of the program I got a completely different message – some useful information describing a 10 year study on diet which shows modest-to-none improvement irrespective of low fat, high GI, high carb, fibre-based diet etc.

    The point made in this second half was that our body automatically self-regulates if given high fat or high sugar separately.

    But the real killer is the combination of fat and sugar together, since it suppresses the automatic self-regulating but stimulates the rewards system (hence by implication making us vulnerable to over-ingestion of calories – my words not theirs).

    A 50/50 blend proves to be the most rewarding – yet also the worse for self-regulating. Curiously this is particulaly prevelant in ‘favourite’ processed foods.

    The article and comments mostly appear to be totally annoyed by the first half of the program – what sounds like a unhelpful twins experiment.

    Some valid science it seems, but perhaps has to be filtered from the ‘hype’.

  83. Michael 31 January 2014 at 6:36 pm #

    Thanks for a great review – I agree with all your sentiments here. One important point that you may have missed is that the “high fat” diet he was on looked far like “high protein” to me. To compare high fat versus high sugar diet without keeping protein constant is a major flaw. How do we know that the effects are due to high fat and not high protein? I always feel sick when I eat too much dense proteins – especially chicken and this seemed to be his main dish.

  84. fennel 31 January 2014 at 6:38 pm #

    It is difficult enough battling with the medical profession to keep healthy and to keep off all the dangerous drugs that are proffered as solutions for all problems. Patients don’t want to be a receptacle for nasty chemicals and to prop up the profits of Big Food and Big Pharma. Some of us pay with our lives or are left crippled.

    The diet and supplements is a good choice and it takes courage and dedication to take this lonely path. This program is intent on further confusing the very confused, and preventing people from discovering how to eat by featuring two very silly diets that are going to make anyone ill. What a pity they did not show us how to eat to keep well instead.

  85. James 31 January 2014 at 7:02 pm #

    The reasoning for this is simple.

    The body senses low glucose and down-regulates insulin sensitivity in the muscles to ensure the scarce glucose is utilised by the brain. Insulin sensitivity in the brain remains the same.

    It is a completely natural response to a low-glucose environment.

  86. TA Greenwood 31 January 2014 at 7:04 pm #

    I had a feeling that the programme was going to “toe the NHS guidelines” when the dietician wheeled out the top 5 ‘celebrity’ diets that the British Dietetic Association say you should avoid: Dukan, Breatharian, Alcorexia, Biotype and Gluten-Free. They wasted a chunk of airtime discussing and dismissing all these ‘fad’ diets, yet none of this info added anything valuable to the “Sugar V Fat” showdown.

    And apparantly – according to one of the Drs – none of us would think of drinking double cream on it’s own or eating spoonfuls of sugar…oh really? I can easily eat/drink double cream – especially if whipped – as though it were yoghurt, and when I was a lot younger I had awful sugar cravings and would eat sugar lumps or sugar from the spoon just to get a “hit”. Just because the good Drs couldn’t imagine it, that doesn’t mean it can’t/doesn’t happen,

    I too would love to see the Drs’ starting and concluding test results, a breakdown of how they felt during each day of the ‘study’ (because their video diaries were seriously lacking in substance and quantity!), and a list of exactly what was eaten and when.

  87. Jennifer 31 January 2014 at 7:32 pm #

    Oh, my maths got the worse of me…..1:2 ratio, of course.

  88. Sue Gooch 31 January 2014 at 7:34 pm #

    Neutral I’m sure it’s a truth that if you exercise like an athlete you’ll be as fit as an athlete and likely as slim. The other truth is that only athletes train like athletes the rest of us try to fit exercise round everything else in our lives. Some manage way more than others probably in the misguided notion that it will aid weightloss, the simple truth is that that theory has been disproved many times over.

    Consider, one lb of weight equals 3,600 calories. Most exercise burns approximately 450 calories per hour at medium intensity, that’s equal to 7 hours of exercise to burn off one pound. That’s an hour 7 days a week or whatever multiples you like. The only other thing you can do to aid weightloss in this situation is to also cut back on your calorie intake which is where it starts to fall down because once you stop, the weight goes back on and as the majority of “diets” restrict fat rather than carbs then hunger becomes an issue.

    Don’t take my word or Dr. Briffa’s, google can confirm it too. I, personally, am getting very fed up of this constant mantra especially when it’s being promoted by so called diet experts both on TV and in other media.

  89. George Henderson 31 January 2014 at 8:01 pm #

    We are told how much fat and how much muscle each twin lost, but (I’ve not seen the program, only read the analyses online) is there any mention of water weight loss?
    Couldn’t this be the non-fat weight lost by “fat” twin?

  90. Curt 31 January 2014 at 8:32 pm #

    Hey! Didn’t this whole sugar vs fat thing play out in the 1960′s between a couple of scientist…Ancel Keys from America, who put the fear of fat into everyone, and John Yudkin from Britain, who tried to correct Ancel and warn everyone about the dangers of sugar. Oh wait a minute, the twins said the Brits thought the problem was with fat and the Americans thought the problem was with sugar. Ahhh, a little role reversal now. Hmmmm, I’ll go with Sweden…at least someones government and scientists are finally on the right track.

    I’ll also stick with my low-carb life style so that I don’t have to give my self insulin injections anymore.

    The twins confirmed at the end of the show that doctors don’t always know much about diet and nutrition. If you want something done right, you gotta do it yourself…being healthy is a do it yourself project!

  91. Angelo 31 January 2014 at 9:19 pm #

    I just went thru 92 comments looking for a rebuttle from Dr McKenzy after Dr Briffas comment in a reply to Dr McKenzys comment. I found nothing. I guess Dr. Briffa told him eh.

  92. Allen 31 January 2014 at 10:20 pm #

    If its not enough for the NHS to be filling our lives with poor advice, we now have the BBC wading in as well with a quite frankly ridiculous slant on what could have a really informative study.

    Worse part is it doesn’t end there – has anyone questioned or looked at what were are teaching our children about nutrition in schools.. Am quite simply fed up with the level of misinformed misinformation that is peddled by these snake oil folk who are being paid by use to keep us unhealthy and obese.

    So come on then Dr Mckenzie – stop hiding away – where are you now to defend your published expertise in the face of those people who have something better – its called real life hands on experience

    Power to your Blog “Dr B and thank you once again for being the champion of the vast unheard and growing number of people who know better than a published (probably entirely academic) Doctor.

  93. Lesley 31 January 2014 at 10:27 pm #

    Thank you for this nice review of the programme. I was hoping you would do a post on this. Like many who have responded I have been successful in losing weight and maintaining weight loss by limiting intake of refined carbs and starchy foods and i think your books are excellent summaries of the science supporting this approach to diet and health. It saddens me to see overweight people still struggling along on low fat, low calorie regimens and this Horizon programme will only set back public understanding of the compelling carbohydrate hypothesis of weight gain and ill health. Before seeing it I was hoping that the Horizon team would bring this to wider public attention, as they recently did with intermittent fasting, but the programme was simply bad science, very badly presented, and dangerously misleading. The BBC, if it believes it plays any role in public health education, should be ashamed about this.

  94. Brian 31 January 2014 at 10:50 pm #

    What surprised myself about the test study was the high fat dieter was told not to eat vegetables? The high sugar dieter was told to eat as much fruit and veg and they wanted? No greens – wher