We all know that fat is fattening right? (It is called fat, after all.) But not so fast, because as I detail here, for fat to get ‘fixed’ in the fat cells, a substance known as glycerol is required. Glycerol itself is supplied from a substance known as alpha glycerol phosphate (also known as glycerol-3-phosphate), which itself comes from the metabolism of glucose (carbohydrate). It should also be borne in mind that for sugar to get into the fat cells in the first place insulin is required, and this hormone is secreted most plentifully in response to the ingestion of carbohydrate.
The insulin secreted in response to carbohydrate (but not fat) also affects enzymes in a way which inhibits fat breakdown and enhances fatty deposition in the body.
So, one line of argument goes that eating a glut of carbohydrate (not fat) is what is truly fattening. It’s not a new message: most of us will have heard this concept before if we’re at all familiar with the work of the late Dr Robert Atkins, and at least some new life has been breathed into this idea through the work of Gary Taubes (author of Good Calories, Bad Calories/The Diet Delusion).
The idea that fat may not be intrinsically fattening received some support this week in the form of a study which assessed the relationship between dietary fat levels in almost 90,000 European adults and changes in body weight [1]. Individuals were followed for several years.
This study looked at the relationship between total fat intake and weight change, as well as the relationship between different types of fat (saturated, unsaturated and monounsaturated) and weight change too.
Once appropriate so-called ‘confounding factors’ such as dietary and lifestyle factors were taken into account, the authors could find no association between total fat intake or intake of any specific type of fat and weight change. They concluded We found no significant association between the amount or type of dietary fat and subsequent weight change in this large prospective study. These findings do not support the use of low-fat diets to prevent weight gain.
Epidemiological studies of this nature are not necessarily the best way to adjudge the effect of dietary fat on body weight. The acid test is really to, say, put people on low-fat diets and see if they successfully lose weight in the long term. A major review of relevant studies showed that, by and large, they don’t [2]. This study, undertaken by scientists from the respected Cochrane Collaboration, was withdrawn in 2008. The reason? It was out of date, and that the authors had no intention of updating it.
There are plenty of studies out there that might be viewed as ‘out of date’, but if there’s no new evidence to challenge their findings then, as long as the research has been performed appropriately and honestly, then they should surely stand. Back in 2002 the evidence clearly showed that low-fat diets are not effective for the purposes of weight loss, and the reality is nothing has changed now.
Some might argue that while reducing fat intake is ineffective for weight loss, it might however be more effective regarding fat loss specifically. This question was considered by a major review conducted at the Harvard School of Public Health in the USA [3]. After reviewing literally dozens of studies which examined the relationship between fat eating and body weight, as well as the effectiveness of low-fat diets, the authors concluded that Diets high in fat do not appear to be the primary cause of the high prevalence of excess body fat in our society, and reductions in fat will not be a solution.
For individuals seeking to shed fat effectively in the long term, getting control of insulin levels is often key. This generally means cutting back on carbs, particularly those most disruptive to blood sugar and insulin levels such as those with added sugar and starchy staples such as bread, potatoes, rice, pasta and breakfast cereals. Another huge benefit associated with the eating of such a diet is that people often end up eating less, quite spontaneously and, importantly, without hunger.
References:
1. Forouhi NG, et al. Dietary fat intake and subsequent weight change in adults: results from the European Prospective Investigation into Cancer and Nutrition cohorts. Am J Clin Nutr 14 October 2009 [epub ahead of print]
2. Pirozzo S, et al. Advice on low-fat diets for obesity. Cochrane Database Syst Rev. 2002;(2):CD003640
3. Willett C, et al. Dietary fat is not a major determinant of body fat. Am J Med. 2002;113(9B):47S-59S
There is a very interesting video on You Tube
The Battle of the Diets: Is Anyone Winning (At Losing?) in which Chris Gardner from Stanford University compares Atkins diet to Ornish Zone and LEARN diets.
About 17 minutes into the talk he shows pie charts representing the proportion of protein fat and carbohydrate between the diets and how people ended up after a year of following each plan after active support had been withdrawn.
His research showed clearly those following Atkins, eating the most fat and fewest carbs, achieved the best results.
I’m sure cutting fat isn’t the only way to lose weight – but increasing carbs and cutting fat sure works for some. You only need to check out the Slimming World diet where it is possible to eat a massive amount of carbs (on a green day) with a relatively small amount of fat, and the amount of people loosing weight on this is huge.
Horses for courses?
but alas! in these harsh economic times, the fact that dairy products, meat and fish cost more than carbohydrates, especially the staples, puts a low carb/high protein diet beyond many people’s reach
Alice
“Horses for courses”
To a degree: I agree that the ideal diet varies from individual to individual. However, taken as a whole, the evidence shows two things, I think:
1. Low-carb generally out-performs low-fat for weight loss (and also biochemical markers of health)
2. Low-fat is generally ineffective for weight loss in the long-term
Alice is right. “Increasing carbs and cutting fat” is the right approach for insulin sensitive people who are overweight. Insulin resistant people need to use a different approach.
At about minute 40 of the lecture Ted linked to above Dr. Gardner discusses a few papers showing that insulin sensitive people do better on high-carb diets than they do on low-carb diets, whereas the insulin resistant do just the opposite.
There’s an interesting parallel to this in “Nutrition and your Mind” by George Watson, PhD. Dr. Watson tested patients’ venus blood ph and CO2 levels and was able to distinguish fast burners from slow burners, as he called them. They needed opposite fat/carb ratios for their cellular machinery to function properly.
I wish people involved in the low-carb/low-fat debate acknowledge that successful weight control requires that the dietary approach be tailored to the individual’s peculiar biochemical ans physiological makeup.
I agree with Alice regarding losing a lot of weight on Green Days at Slimming World from my experience of the stories told in class from my fellow Slimming Worlders. Personally I lost over 7.l/2 stones following mainly Original Days(low fat protein). Therefore I can wholeheartedly recommend Slimming World.
Could you expand further on this statement?
“The insulin secreted in response to carbohydrate (but not fat) also affects enzymes in a way which inhibits fat breakdown and enhances fatty deposition in the body.”
I am curious how this happens as all fat enters the body as triglycerides are 3 fatty acids to one part glycerol. My understanding from Good Calories Bad Calories is that fat cannot enter a fat cell nor leave the fat cell as a triglyceride. It enters and leaves as fatty acids.
David/Janet
Please see comment 5.
MAC
You’re right, I think, about the fatty acid/triglyceride thing. Glucose provides the glycerol that is necessary to convert fatty acids to triglyceride – effectively ‘fixing’ fat in the fat cells.
Regarding insulin, it:
activates acetyl co-A carboxylase (which stimulates lipogenesis)
activates lipoprotein lipase (which also stimulates lipogenesis)
inhibits hormone sensitive lipase (which inhibits lipolysis)
Thanks for the explanation. The statement I asked for clarification on just really says what you have have been saying. Fat storage is enhanced by carbs via insulin as glycerol is present to fix the fatty acids in the fat cell. I just read it as being something new above and beyond what I new about fat storage. Still early here in the States.
Well, for many years I avoided ‘fats’; the only one I used was virgin olive oil, along with a generally healthy diet and various ‘supplements’. In 2004 I was told I had a “very low tolerance for sugar”. So, the half teaspoon of sugar I used a day, in coffee, was ditched and I scoured the labels on food even more fastidiously – didn’t use salt, or sugar & avoided anthing ‘added’. BUT, after reading Dr Briffa’s advice about ‘fats’, I resumed eating butter and increased my milk consumption from skimmed to semi (for coffee only). And, guess what – my cholesterol & blood sugar increased. And, just a couple of months ago I had a ‘heart attack’. So, Dr Briffa, having been a devoted ‘follower’ from when you wrote a weekly article in the Observer – I have become EXTREMELY sceptical about your mantra about fats being OK.
“puts a low carb/high protein diet beyond many people’s reach”
A proper (healthy) low carb diet isn’t high protein, it’s high fat/moderate protein.
I’m finding zero carb (carnivorous) more affordable than my previous mixed diet.
Dr Briffa, I am always interested in your research on weight loss. About myself and past….I had the STAPLE OPERATION in 1984, I had lost wieght but put it back on and more….I found the problem was they didn’t realise I needed pychologial support to adjust to the huge change. Also I had tried many many diets, nutritionists etc. I am now 50 yrs old. I have learnt alot from experience and listening to others with similar problems. It is obvious we can not generalise as obesity has become a huge issue all around the western countries…..we over eat due to stress, a hectic lifestyle, or some people have glandular health condition etc….. For me it is like many I turned to ‘COMFORT FOOD’ The usual fatty, and sugary foods when I was down, depressed or stressed out due to a hectic lifestyle……Since many years of trying to work myself out I found like many I had to slow my life down, learn to understand my reasons for eating these foods. I had to make a decision (and had to be SICK AND TIRED OF BEING A YO-YO) to CHANGE MY LIFESTYLE PERMANTLY. I now do positive things when I am down….I treat myself to look and feel great, help others to do the same, take care what I eat (but not as rigid as I used to be). I still have my yummy foods every now and then. I exercise daily 1-1 1/2 hours but gentle exerise (to my own pace). I associate with positive people or people who want to change their lifestyle too…..Luckly after I had my staple operation it gave me direction that I can lose wieght naturally….as before the op, many people used to say I was BORN THAT WAY AND NEED TO ACCEPT IT…….I have learnt that I had to do my own research of what is good for me, get to know myself better, love myself better and learn to do everything in moderation and balance my thinking and my emotions….to take charge and control my inner thoughts and emotions….so I can cope better with life……since I have been doing this I have become more confident and learnt to stand up to ‘DESCRET BULLIES:- PEOPLE WHO ARE TOO FULL OF THEMSELVES” In life there is so many of them……so with all your research I find it very encouraging to find out I am on the right track and dont have to be so “HARD ON MYSELF” in turn I am appreciating life and others and at the same time I am not so stressed and anxious as I used to be……I believe all of what you have shared with us and the things I have experienced is a WHOLISTIC APPROACH TO PERMANENTLY KEEP OFF EXTRA WIEGHT AND TO REACH MY IDEAL SIZE.
Thank you for all your effort to help so many people with this similar issues. CHEERS TO YOU!!
Paleo evidence backs this blog up – fat is not the bad boy it is made out to be. I look forward to the time when people routinely separate out the consumption of good fat from bad fat. The term ‘high fat’ seems to conjure up images of early Atkins style diets where people would consume big blocks of cheese, cook with lard, eat full fat bacon etc. If we look at Paleo evidence, then our high fat generally came from nuts, seeds, organ meats, fish, low saturated fat on the flesh of wild animals, etc.
It would actually be a lot more helpful (though less user friendly) to talk about ‘fat’ in terms of the individual fatty acids as some are healthful & necessary, whilst others are very damaging. But instead we have vilified this unbrella term – fat. We need to do the same with carbohydrate to a certain extent too… glucose good/ok, fructose – not so much. Sometimes our need to simplify things down means the message is altered.
Nice evidence Dr Briffa. Great site.
Rita Schembri – you are an inspiration to all mankind!
Good on you for getting on the right track and taking such a positive approach to living a healthy life.
Best wishes 🙂
If carbohydrate is necessary for fat to be stored as bodyfat, answer me this:-
If you eat 50g of butter (or drink 40g of oil) and nothing else, you’ve ingested 40g of fat (~360kcal) and nothing else. As fat alone doesn’t produce an insulin response, where does the fat go?
It isn’t lost in the breath (even in deep ketosis, only a few kcals/day are lost this way).
It isn’t lost in sweat.
It isn’t lost in urine (even in deep ketosis, only a few kcals/day are lost this way).
It isn’t lost in faeces (unless you’re taking Xenical etc).
My guess is that fat cells are sufficiently sensitive to insulin that they can take in glucose from the blood even with basal insulin levels. The liver produces glucose from the glycerol backbone of triglycerides so blood glucose doesn’t drop. Therefore, Calories still count.
That said, I am one of those people who gets fat if I eat too much sugary/starchy carbohydrate. This is due to my appetite increasing, making me eat more.
Cheers, Nige.
Nigeepoo
“where does the fat go?”
one possibility is that it’s metabolised
SMc
I’m sorry to hear about your recent heart attack.
However, cardiovascular disease has a long latency, generally, so it’s possible that it was your years of avoiding fats (not your more contemporary dietary changes) that was a critical factor in your heart attack. I’m not suggesting this is true. The point is, we just can’t really know one way of the other.
Because drawing conclusions from individual experience is fraught with difficulty, I try as much as possible to base my nutritional advice on published evidence. I can’t prove a negative (i.e. I can’t prove that saturated fat does not cause heart disease). However, it is theoretically possible to demonstrate that saturated fat DOES cause heart disease. Would you care to present that evidence now?
“Dr John Briffa says:
Nigeepoo
“where does the fat go?”
one possibility is that it’s metabolised”
Cholesterol synthesis requires only a few g/day of fat. Steroid hormones incl Vit D3 are synthesised from cholesterol. What is dietary fat metabolised into if it isn’t stored?
Cheers, Nige.
“What is dietary fat metabolised into if it isn’t stored?”
Energy, perhaps?
Dietary fat is only ~3% thermogenic so metabolic rate hardly rises when fat is eaten. If a sedentary person is using energy at a rate of ~1kcal/min, that’s not going to increase sufficiently to burn 360kcals worth of fat before the next meal.
Although I believe that low-carb diets are the best choice for sedentary people and people with Insulin Resistance, Metabolic Syndrome & Diabetes types 1 & 2, I don’t believe that a Calorie is not a Calorie. Please read (if you haven’t already):-
http://www.bodyrecomposition.com/fat-loss/is-a-calorie-a-calorie.html
also
http://www.bodyrecomposition.com/fat-loss/the-energy-balance-equation.html
Any comments?
Faeces do, in fact, tend to contain a lot of fat/calories, which is why animal dung is used as fuel in many countries. I did not know the mechanism that caused fat excretion in slim people and fat retention in fatter people, though I did guess that it probably involved minerals in the diet, because fat people, i.e. people with fluid retention, tend to be deficient in calcium, magnesium and potassium.
A few years ago BBC2 showed a series of programmes called “The Truth About Food” and I learnt about some Danish research which throws light on this. ” See http://www.bbc.co.uk/sn/humanbody/truthaboutfood/slim/calcium.shtml where you will read: “a high calcium intake increases the excretion of fat in the faeces”. ” There was the necessary information! ” In fact, the researchers found that twice as much fat was excreted on a high calcium intake as on a low calcium intake ” and this was independent of calorie intake. ” They also found that dairy calcium (they suggest low fat yoghurt) is a particularly good source for this extra calcium.
On one of the links – http://www.vitamins-nutrition.org/vitamins/calcium.html – from the BBC The Truth About Food site, it says: “Calcium is the mineral most likely to be deficient in the average diet. Let me repeat that. Calcium is the mineral most likely to be deficient in the average diet. Calcium deficiency is a condition in which we fail to receive or to metabolize an adequate supply of Calcium,” and also: “Calcium helps keep the weight off. Research suggests that if you don’t get enough calcium in your diet, you’re likely to be overweight.”
There are a number of reasons that overweight people in particular tend to be deficient in calcium. The main reason is that sodium retention/salt sensitivity/fluid retention depletes the body of calcium.
Here are two other very simple reasons:
1. Most fat people are ‘dieting’ most of the time ” i.e. they are eating insufficient food for their body’s needs.
2. Fat people are routinely advised to limit their intake of dairy food like milk because their advisors (wrongly) believe that milk is ‘fattening’.
So to reduce fat retention, if it is present, the most important thing is to alter the diet to reduce the fluid retention which is the initiating cause of excess weight and the primary reason for fat people being short of calcium and for fat people ‘dieting’. That means reducing sodium intake and ensuring plenty of fruit and vegetables in the diet (because their high potassium content helps to displace sodium from the body).
And specifically it also means having a higher intake of calcium, especially, if possible, from a dairy source like low fat yoghurt. ” It is also necessary to ensure sufficient vitamin D intake, as this is needed to metabolise the calcium.
Dr Briffa, I have a question and I have been trying to work out on how to ask this question…….Is there a possible chance for each individual that has a eating disorder, to gain weight through their way of thinking (mental attitudes, eg negative, worry, parinoia, anxiety and stress) would this create a highly chemical imbalance and with the combination of certain foods we eat affect certain organs in our bodies not to function as they should…..in fact slow them down…..eg….our metabolism???? The reason I ask is so much reseach has been done over so many years by so many doctors, nutritionists, and scientists that no one has a very acurate answer. So therefore could the issue be more deeper than what combination of foods we eat…..as I know some people who can eat and eat and not excerise much and not gain an ounce……I know that since I have been focusing on changing how I think and trying to think much more positive I am controling my wieght gain and am losing wieght slowly and safely…..this is the main reason I have shared my experiences of my past and not to brag but to see if it could help others who have tried all their lives fighting with this same problem……I thank my mum for helping us to believe in God as it has helped me not to give up when I have been so down……my goal is I will lose my wieght to feel better about myself and how I look and feel….my acheiving CONTROLING MY EMOTIONS AND THOUGHTS IS WHAT IS MAKING ME HAPPIER, AND IN TURN I DONT WANT TO EAT AS MUCH SUGARS, FATS OR STARCHY PRODUCTS…..I still crave for them on occation and I do have some at times BUT I AM AWARE not to go to far. I have a mental illness, Manic Biapolar. I take Eplim and Serexat daily….I have gone through periods of not wanting (feeling) able to go even for a walk or even clean the house…..but by focusing on improving and controlling my IMAGINATION to better myself and my life (also through my faith-catholic) I am so happy and thankful to God to have this wonderful gift (like many of us have) God is teaching me to use my imagination in a positive way. We were never taught how to use our imagination at a young age and i guess this is why many of us ended up with depression, or mental illness or surrounded with so much negativity around our societies and around the world….but finually there is alot of marterial and resources that has to offer for all of us……so to all those who are reading and have gone through similar experiences as I have focus on your imagination, have faith and hope in your self and try to believe that God is real and is there to help you., in your difficult moments…..you can not do it alone. You can only try it out and see if will help you…..as Saint Padre Pio used to say:- “PRAY, HOPE AND DON’T WORRY!!” Then you use this in your imagination to become this and life won’t seem so difficult…..situations will get better……Best Wishes to all….. and Dr Briffa thank you so much in all your efforts in trying so hard to find out if there is much deeper causes for some people that find it hard to lose wieght/ easy to gain wieght……thanks Michelle for your kind gesture!!
CHEERS TO ALL!! 🙂
“Margaret Wilde says:
Faeces do, in fact, tend to contain a lot of fat/calories, which is why animal dung is used as fuel in many countries….
A few years ago BBC2 showed a series of programmes called “The Truth About Food” and I learnt about some Danish research which throws light on this. ” See http://www.bbc.co.uk/sn/humanbody/truthaboutfood/slim/calcium.shtml where you will read: “a high calcium intake increases the excretion of fat in the faeces”…. In fact, the researchers found that twice as much fat was excreted on a high calcium intake as on a low calcium intake”
Dear Margaret.
Define “a lot”. Human dung has a different composition from herbivore dung (herbivores being the types of animals herded by humans).
I watched “The Truth About Food” but absolute amounts were not mentioned. However, I found this:-
http://www.ncbi.nlm.nih.gov/pubmed/19493303
In the high calcium group, there was an increase in faecal fat of ~5.2g/day. If this was double the amount in the low calcium group, this implies that the absolute amounts were ~5.2g/day and ~10.4g/day respectively. Not a lot IMO.
Lots of fat in faeces causes steatorrhea (a.k.a. “soily oilies”) a most unpleasant condition.
Cheers, Nige.
Hello Nige
The people eating the low fat yogurt in the BBC2 Truth About Programme DID ALL lose weight – healthily and safely – and the yogurt they ate was extra food intake, not substituting for other food. That was a good demonstration in practice that cutting down on food intake/dieting/cutting calories is not necessary for healthy loss of weight and that ‘overeating’ is not the reason that obesity is on the increase.
If the subjects had had lower intake of salt they would have lost more weight and also more fat, for the reasons explained in my earlier post and on much more fully on my website.
As a very disabled, house-bound steroid victim in constant severe pain, especially my hands, making typing an ordeal, I’m not looking for an academic argument or seeking to score points off anyone. I post comments to be helpful, and I know the sodium reduction and calcium increase information has helped many people – people sometimes in desperate need of that help.
Hi Margaret,
I’m not disagreeing with you that many people are deficient in Calcium, Magnesium & Potassium and have excessive amounts of Sodium in their diets. I supplement with 600mg/day Calcium, 300mg/day Magnesium and use Lo-Salt (66% Potassium, 33% Sodium) in cooking, as I do eat high-sodium foods like bacon and smoked salmon.
I’m just querying how much dietary fat is lost in faeces. I’m not looking for an argument either.
Cheers, Nige.
Found a great study for you to mention on your blog if you’re interested! http://docs.google.com/gview?a=v&q=cache:7Ko92oT4Y1oJ:www.mdpi.com/1660-4601/6/10/2626/pdf+food+choices+and+coronary+heart+disease:+a+population+based+study+of+rural&hl=en&gl=us&pid=bl&srcid=ADGEESjymjTR82Q9lmcgGMInyuCM-COg90NQRBcw5k1iNoyLsoZI5XFbZ6bbVcdPNx7T1H99LYsjggezmpwDWaVfXZsTF6n3-0dVFs9BGTzNAsh7nYm32stE0osXuNbpAD2IL-p5NmIp&sig=AFQjCNGftJ88PuYVcT12VO-6b6Xs3u2gTg
Food Choices and Coronary Heart Disease: A Population Based Cohort Study of Rural Swedish Men with 12 Years of Follow-up
The BBC programme The Truth About Food was an interesting series, much of it’s content had merit and if it it raised the level of interest in the audience to the point that they may have taken up with further reading then that would have been a virtuous result. There was a book by the same name. The programme was not without fault and the conclusions discussed following the Paignton Zoo experiment was a case in point. Some variables were omitted from discussion.
The Truth About Food was good informative television better for being broadcast on a public service channel devoid of periodic advertising for margarines, probiotics, or chocolaty breakfast cereals featuring some charming cartoon character.
Far from being excellent, The Truth About Food was good enough to deserve a sequel, The REAL Truth About Food. I have no knowledge that such a programme has been commissioned.
The four part George Alagiah fronted ‘Future of Food’ was a much more pertinent offering. I did wonder if the Beeb or producers conceived of this programme entirely independently or if they received a nudge from the machinery of state. No matter, the sustainability debate needed to be opened up and it did that.
Rita, the link between food and mood is a strong one, especially in overweight and insulin resistant people. There is mileage in wondering if countering hyper-insulinemia can reduce the cravings. Anxieties, insecurity, unhappiness, or lack of FAITH would be perfectly reasonable candidates as suspects that would contribute to a loss of self regulation of appetite.
Physiologist Paul McKenna has authored a book ‘I Can Make you Thin’ which addresses weight loss by challenging anxiety and general rushing amongst other things. Kathleen Desmaisons has titles which focus upon the addictive nature of sugar and carbs with suggestions as to how to deal with the cravings. I found her offerings quirky but pertinent.
‘The Biology of Belief’ by Bruce Lipton may well give you direction and confidence to answer your own question; FAITH and self belief WILL positively impact upon your future health outcomes. The religion thing does not float my boat. For some religion is powerful. I believe in freedom of religion. I will happily big-up FAITH.
I have an acquaintance who was crippled by chronic fatigue syndrome; he studied Buddhism, became fully involved and found strength in it. He wrote about the experience in ‘Everything Is A Blessing’ (David Vennells)
I am certain everyone here would join me to wish you success. I could use your help, returning to night work has stunted my progress. 🙁 …. ;-))
I really do not understand the way that medics clutch to the “calorie is a calorie” mantra. If you look at the remains left in a glass vessel that has had a foodstuff burnt in oxygen to measure calories; there are virtually none. So the calorific value is when a food is TOTALLY burnt in oxygen. One glance into the toilet pan in the morning shows this does not happen in our bodies!
We all know that certain foods “pass through” more than others. So calories in high pass through foods must have less affect on our bodies than other calories that are more completely digested. Why has this not been investigated, it must have the potential to make massive contributions to our understanding of obesity.
Greg Carlow said:
I really do not understand the way that medics clutch to the “calorie is a calorie” mantra.
We all know that certain foods “pass through” more than others. So calories in high pass through foods must have less affect on our bodies than other calories that are more completely digested. Why has this not been investigated, it must have the potential to make massive contributions to our understanding of obesity.
Hi Greg.
The reason that many medics and I believe that “a Calorie is a Calorie” (as far as weight is concerned) is because that’s what studies show, where food intake is rigorously controlled. Where food intake is self-reported, results are wildly inaccurate.
See Lyle McDonald’s articles linked in post 21
Also, see Anthony Colpo’s article “They’re all MAD”
http://www.thefatlossbible.net/They_Are_All_Mad.pdf
The nutrients (and therefore Calories) in foods are almost 100% absorbed. The only nutrient that isn’t absorbed is fibre, which is why on UK food labels, fibre isn’t included in the carbohydrate content (it is on US food labels). Insoluble fibre provides zero Calories and ends up down the toilet. Soluble fibre provides some Calories as it ferments into fatty acids, some of which are absorbed. A *very* high fibre content in the diet can reduce the absorption of other nutrients but this tends to cause diarrhoea & severe flatulence due to osmotic atttraction of water & fermentation of non-absorbed nutrients in the colon.
Cheers, Nige.
Nice find Dr Briffa. It’s a step in the right direction, isn’t it?
Now for your skeptical readers.
Why do we grow fat? Is it because we eat more? Or is there’s something else going on that fudges things?
Why does a child grow up? Is it because he eats more? Or is it because there’s something else going on that fudges things? How about growth hormone, that makes kids grow, doesn’t it? So why does he eat more then? Is it because the growth must be compensated for? Yes, that’s exactly it.
So then, why do we grow fat? Because of insulin. As insulin does its job of locking fat away, we have less fuel available, we get more hungry, we eat more. The association is still there (eat moregrow fat), but the causality is reversed (grow fat>=>eat more). Not only do we eat more because there’s less fuel available, but we eat more because the system is growing bigger and a bigger system requires more fuel.
Cutting calories? Sure, but that doesn’t work since fuel spent will just be reduced to compensate. I.e. We will become lethargic. So how do we reduce system size then if not by cutting calories? By altering the hormones that control system size. In this case, it’s insulin. Control insulin, control system size. So how do we control insulin? By controlling carbohydrate intake.
But what about dietary fat? Well, it barely registers on the insulin scale. How could something that is barely effective at altering the hormones that control system size ever be responsible for the growth of the system? No, dietary fat has little, if any, effect on system size. However, it does have an effect on available fuel. If you followed the whole shebang up to here, then you know about calories out. What if you could increase calories out without exercise? Yes, that’s right: Eat more fat. Don’t believe me? Here’s the logic. Dietary fat has no effect on insulin so it can’t cause fat accumulation yet it provides a boatload of fuel thereby increasing fuel spent, we become more active. More calories out.
Ooh, that’s a total shift of paradigm. You don’t say. Hehe.