Study suggests that low-carb diets can bring long term benefits for type 2 diabetics

The body likes to keep its internal environment quite stable, and this includes the amount of sugar circulating in the bloodstream. The chief blood sugar lowering hormone is insulin. In diabetes, there can be a problem here leading for blood sugar levels to be higher than is healthy. Diabetics either don’t have enough insulin, or it’s not working particularly well, or both. As a result, blood sugar levels tend to be high, and this in the long term can lead to a variety of issues including eye disease, kidney disease, nerve damage, heart disease and premature death.

The fundamental source of sugar in the body is foods that contain sugar and/or starch (carbohydrates). So, common sense dictates that if diabetics are looking to keep their blood sugar levels under control, they may naturally look to a diet relatively low in carbohydrate. Even without any nutritional knowledge whatsoever, I suspect you’ll still be with me so far. The problem with this area is, I think, that many individuals who profess to have nutritional knowledge often claim that it’s important for diabetics to eat carbohydrate such as bread, potatoes, rice and pasta with every meal.

My experience is that diabetics that act on this advice have a generally hard time in regulating their blood sugar levels. It’s not just my experience that causes me to question the conventional dietary advice given to diabetics, its also what is to be found in the scientific literature. There has amassed to date a considerable body of evidence which shows that diets lower in carbohydrate produce better results in terms of blood sugar control than diets higher in carbohydrate

So, why is this advice dished out so frequently? Well, one ‘defence’ of the ‘diabetics need starchy carbs’ line of thinking is that the long-term effects of carbohydrate restriction are unknown. The suggestion here is that a lower-carb diet is one that is likely to be high in fat that is going to put diabetics at risk of heart disease. First of all, low-carb diets are not necessarily high in fat. And even if they are, fats found naturally in the diet don’t have a strong link with heart disease. And even if they did, any increased risk here may be more than offset by eating a diet that reduces the impact diabetes has in the body, which would likely reduce the risk of heart disease.

Bearing in mind the reticence some still have to suggesting a carb-controlled diet for diabetics because of lack long-term data, I was interested to read a study that has recently been published on-line in the journal Nutrition and Metabolism [1]. This study was actually a continuation of an original piece of research which pitted a low carbohydrate diet (20 per cent carb) against a higher carb diet (55 per cent carb) in a group of obese type 2 diabetics over a 6 month period [2] .

The results of this original study showed that the lower carbohydrate diet led to significant improvements in body weight and blood sugar control (glycaemic control) compared to the higher carbohydrate diet. After the initial study was over, the researchers assessed these individuals again in another 16 months (a total of 22 months), and discovered that the benefits seen after 6 months had been broadly maintained [3].

In this latest study, individuals who were originally put on the lower-carb diet were assessed again, this time a total of 44 months after the initial trial started (and more than 3 years after the initial trial ended).

Compared to how they were at the start of the original study, these individuals were found to have:

Significantly lower body weight ” an average reduction of 7.5 kg or 16.5 lbs

Significantly lower levels of HbA1c (which gives a measure of blood sugar control over the preceding 2-3 months) ” the reduction was from an average of 8.0 per cent to an average of 6.8 per cent.

Significantly higher levels of high density lipoprotein (HDL) cholesterol ” believed to be a marker of reduced risk of cardiovascular disease

Significantly lower total cholesterol: HDL ratio ” which would also generally be taken as a sign of reduced risk of cardiovascular disease

The study also reports on the fact that many individuals were able to reduce or even stop their diabetic medication as a result of the lower-carbohydrate diet.

The current study is hampered by its relatively small size (only 16 individuals started the lower carb diet at the very beginning). Also, the ‘control group’ (those eating a higher carb diet) were only properly in place up until the 6 months stage, after which most of them converted to the low-carb diet (the results that I’ve presented above exclude these individuals).

All-in-all, though, this study I think provides support for the idea that carbohydrate control is effective for the management of diabetes in the long term. It also provides no evidence at all that such a diet is anything but safe as far as cardiovascular disease (heart attacks and strokes) is concerned.

Guidance for those wishing to comment on this blog post:

This blog post is about the use of low-carbohydrate diets in the long-term management of type 2 diabetes, and some of the evidence that supports this approach. If you have a comment to make, please make sure it’s about this subject specifically. In particular, if you disagree with the views I express here, then I encourage you to debate this using science.


1. Nielsen JV, et al. Low-carbohydrate diet in type 2 diabetes: stable improvement of bodyweight and glycemic control during 44 months follow-up. Nutr Metab (Lond). 22 May 2008 [Epub ahead of print]

2: Nielsen JV, et al. Lasting improvements of hyperglycemia and bodyweight: low carbohydrate diet in type 2 diabetes. Ups J Med Sci 2005;110(2):179-83

3 Nielsen JV, et al. Low-carbohydrate diet in type 2 diabetes. Stable improvement of bodyweight and glycemic control during 22 months follow-up. Nutr Metab (Lond). 2006;14;3:22.

17 Responses to Study suggests that low-carb diets can bring long term benefits for type 2 diabetics

  1. Anna 11 June 2008 at 5:29 pm #

    I use a restricted carb (low in sugar and starches, simple or complex) diet to keep my blood glucose in a tight normal range, without medications. If I didn’t, and ate as the conventional wisdom and many doctors and dieticians advise, I would be diabetic. It’s that simple. It isn’t a matter of not getting enough whole grains (in my prior higher carb diet I ate far more whole grains than refined).

    To those who are naysayers, I respond, then why was this restricted carb diet prescribed by my doctor while I was pregnant? If it is good enough to nourish, gestate, and produce a healthy baby (not to mention keep me in good form), then it is probably good enough for the rest of my life.

  2. Vivian 12 June 2008 at 4:54 pm #

    These results don’t surprise me at all.

    Like Anna, I also use a restricted carb diet to control my diabetes. My lastest A1c was 4.9 with no meds! I started low-carbing (paleo variety of low-carbing – no sugar, very low starch, no grain, no legumes, no dairy (except the very occasional peice of cheese…), no processed foods, all organic, free-range) within a week of being diagnosed. Along with achieving tightly controlled blood glocose levels, I ditched my high blood pressure meds and brought my LDL levels way down and my HDL levels way up. And I maintain my weight loss with little effort and no hunger.

    It’s beyond frustrating that so many in the medical and nutritional communities are unaware/unintereested in this approach to diabetic control (including my own physician and diabetic counsellor).

    Low-carbing for diabetics truly seems to be nothing more than common sense – diabetics don’t process carbohydrates properly – why would they be counseled to keep eating them in the same manner as non-diabetics? Why would anyone expect diabetics to remain healthy eating food products they cannot properly process?

    The excuses I’ve listened to are these:

    “People can’t stick with that approach, so we don’t discuss it.”

    How about giving patients the information they need to allow them to decide for themselves, whether they want to restrict carbs or take meds (or some combo)? How are they ever going to ‘stick’ to an approach they aren’t informed of?

    “People need carbohydrates to stay healthy”

    I’d dispute that, however it is very easy to get more than enough carbs with vegetables and berries. There is a whole world of non/low starchy vegetables out there to discover, once you take the low-carb approach.

  3. Jim Buch 12 June 2008 at 9:47 pm #

    It is interesting that one of the reasons given for hesitancy in recommending low carbohydrate diets for diabetes and for other conditions is the “Lack of Long Term Studies Showing Safety and Effectiveness”.

    What the same people will do instead is to recommend a low fat and high carbohydrate diet. However, this is recommended in the absence of “Long Term Studies Showing Safety and Effectiveness” of the high carbohydrate diet under the same circumstances.

    In fact, the whole shift to the high carb diets for general health was made as a great unproven experiment in public health.

    Ignorance of basic physiology can be a terrible thing. The basic ignorance of fats leads to the fear of fats as a part of the recommended treatment diet. The basic ignorant fear that protein will readily damage healthy kidneys leads to the fear of proteins as part of the recommended treatment diet.

    Therefore, we are stuck with Carbohydrates and Alcohols as the |”Healthy Diet”. Maybe we will correctly deduce that massive amounts of alcohol should be eliminated.

    There fore, we are stuck recommending a high carbohydrate (Processed and Simple) diet, even though there are no long term studies for safety and effectiveness.

    Sounds as though someone is manipulating the rules of “Safety and Effectiveness” unscientificallyly.

  4. Paul Anderson 13 June 2008 at 3:36 pm #

    It is abundantly clear to me that following a low carb diet is the best approach most diabetics can adopt to seek to maintain good control of their condition and to optimize their own health.

    I would regard myself as a work in progress: I was diagnosed with a hba1c of 11 and reduced that to 5.3 within 3 1/2 months. My last 3 readings have been 5.4, 5.3 and 5.4. I do not take any medication, at present. I am not happy with these figures and would like to get down to an hba1c in the mid 4’s.

    I have generally felt so much more healthy, my appetite has signifiantly reduced, and I no longer suffer from cravings. I have lost abouts 35lbs of weight, most of it soon after changing my diet, whilst simulateously gaining muscle, stregth and endurance. I have lost about 7 inches around the waist.

    What has disappointed me has been the very poor standard of treatment available on the NHS. The literature refers to “your diabetes care” team. I do not recognise the existance of any such team. In so far as they do exist their primary role seems to be to worsen my health by recommendation of the absurd high carb low fat diet, and trying to discourage me from testing my bloos sugar – clearly on cost grounds. This is an on-going issue. My nurse also isn’t very happy with my hba1c – claiming its too low for a diabetic. She seems poorly informed and apparently unaware that a hba1c at that level, and higher, heightens the risk of CVD and all death mortality. She is also obsessed with me having hypos when I take no medication, and essentially spend my time trying to do the opposite: to get my BG lower. Even if this fear was well founded, quite how I am supposed to correct for lows when she doesn’t want me to test my blood sugar is beyond me. Of course if I was to run high sugars throughout the day by following her advice this wouldn’t be an issue.

    As a general rule of thumb I instinctively know that whatever course of action the dietition or diabetic nurseirecommends is almost certainly the incorrect one. By adopting this approach I can get some value out of my occasional visits. Otherwise the only value from my visits is to get get tests undertaken so that I can interprete how well or badly I am doing in managing my condition.

    It is frustrating that I can’t get things like vitamin D status, more advanced lipid test (for sub particles) and tests of mineral status undertaken. But at least my doctor allows me copies of the results, which I do my best to interpret. He appers to have little time to do anything other than give the results a cursory glance during or prior to my appointment.

    With regard to the low carb approach, my belief is the lower the better: in the region of 30gs a day or less, along the lines advocated by Richard Bernstein. The more I look in to the need for vitmains and minerals, the more convinced I am that the body requires less of certains vitmains and minerals , eg, vitamin C and some B vitamins, and possibly calcium, on a reduced carb diet. I also believe that the standard low fat high carb diet provides insufficient fat soluable vitamins and depletes the body of vitamin B (some) and C. This is particularly the case for diabtics and those suffering from obesity and metabolic syndrome. This would seem to be backed up by observing the diets of some indiginous communities and by some folliwng versions of the paleo diet.

    Sorry for the rant. Keep up the good work.

    Paul Anderson.

  5. Peter Killingback 13 June 2008 at 7:20 pm #

    It’s worthy of note that if the body is REALLY desperate for carbs it will get them by canabilising protein. There are deamination processes which remove aminogroups from aminoacids(building blocks of proteins) leaving simple organic acids which are then taken into the Krebs cycle, and metabolised to provide energy. This is what happens in extremis when people (really) starve: one loses the fat then the carbs then the protein -ask any survivors of the Imperial Japanese army’s policies in Changi prison in Singapore.

  6. Hilda 14 June 2008 at 1:23 pm #

    With all of the above information from research and also anecdotal data, could one of the dieticians using this site. tell us why a high carb diet is recommended for diabetics? This is not a complaint but a genuine request for enlightenment

    If people in the Paleo age managed to survive and reproduce in such harsh times does this not count as evidence that it is asafe diet? Also a diet high in vegetables contains quite a bit of carbihydrate. The problem is that carbs are seen as bread etc and vegs are in another category but these as well as fruit are also carbs so little danger of getting too few carbs.

  7. John Adler 14 June 2008 at 10:39 pm #

    It makes sense, completely. But what do you recommend for breakfast? Surely one needs a bit of carbohydrate. But how much? I have a small handful of jumbo muesli oats with some fruit for breakfast and it keeps me satisfied til lunchtime.

  8. helen 15 June 2008 at 11:14 pm #

    Charles McGee ( says “The Eskimos gave up their hunting and gathering life style, moved to civilization, and became the labor force. Overnight they switched from an all fresh food raw diet to a diet of 100% processed foods. In a short time of 15 years women were getting gall bladder disease, children crooked teeth and acne, and men heart attacks and diabetes, all conditions formerly absent.”(sound familiar anyone?)…and here’s more…”The anthropologist Stephenson spend many winters living in the North where he ate the Eskimo high fat diet. He returned to New York and gave some lectures about his adventures and observations. Physicians couldn’t believe how he remained healthy on the high fat diet and challenged him. As he had about a year’s writing to do he volunteered to live under observation in a hospital 24 hours a day and eat the same diet for 12 months and be tested, etc. He stayed perfectly healthy as did all of his lab tests, much to the disbelief of the fat theory believing physicians monitoring him” ……& “In a part of Austria everyone who died was autopsied by royal decree. During this same time period American pioneers were eating animals, cooking with lard, and bread spread with lard was a popular food. Guess what? No heart attacks until after 1900 and the MI was not coded as a separate cause of death until 1950 and by that time it was the most common cause of death. When I was writing one of my books I wrote the National Center for Health Statistics asking the question. I got a phone call back with that response. I have been curious about one aspect of the fat theory. We were taught in medical school that we are omnivors, able to eat all foods. We have the biochemistry to process carbs, proteins, and fats. Then suddently we are not able to process a list of high fat natural foods our ancestors ate throughout history with no evidence of harm. Shame on the cholesterol mafia. C. McGee
    well there you go, as Charles McGee found we don’t need to eat carbs at all but I guess for the sake of variation or differences in taste the nutrient dense lower sugar containing plants are probably okay on a limited basis there certainly is no evidence that they are necessary at all unless of course you belong to the grain or manufacturing cartels. Even the theory regarding carb loading for sports people is rubbish disproven by many who switched to low carb high fat & protein diets with no loss of stamina or power some cyclists even reported better times & no hitting of the wall symptoms associated with lactic acid build up common to many sports men & women who carb load before an event.

  9. Sue 16 June 2008 at 5:59 am #

    As much carbohydrate as your body can handle.
    A good breakfast would be an omlette and a handful of berries.
    I’ve been reading that cortisol is high in the morning so eating very high carb in the morning is not advised.

  10. Hilda 17 June 2008 at 10:29 pm #

    ‘As much carbohydrate as your body can handle’ What does this mean? How would one know? To answer John’s question he should have some protein with maybe porridge or rough rye bread or a banana. I dont know if he is diabetic so saying nothing if he is, but it is good for most people to have some proten. I think he should eat more for breakfast.

  11. david Wilson 18 June 2008 at 9:32 am #

    So, because we can now get good feedback by self-testing, thousands of diabetics now have good solid evidence that a low carb diet works – not only for BG levels,but also for cardiovascular indicators.

    Isn’t it time that we got together as a pressure group to challenge the flaky high-carb orthodoxy? And could you, through this excellent blogsite, be the catalyst for it?

    Otherwise we seem fated to remain a mere collection of anecdotes.!

  12. Dr John Briffa 18 June 2008 at 10:43 am #


    Your idea is a good one, I think. I’ll give it some thought. Are you UK-based? Email me on if you wish.

  13. Sue 22 June 2008 at 2:30 am #

    As much carbohydrate as your body can handle – the level that wouldn’t cause such a major blood sugar spike – diabetics can check this with their meter.
    For someone who isn’t a diabetic as much carbohdrate as your body can handle could mean the level of carbs you can eat daily without gaining weight or having sugar cravings etc.

  14. rob clark 2 July 2008 at 3:47 pm #

    ‘I’ve been reading that cortisol is high in the morning so eating very high carb in the morning is not advised.’

    Hi Sue,
    Cortisol is the hormone that helps us wake up, so it is bound to be high in the morning, that in itself isn’t surprising.

    That said, you’re right to say that carbs suppress the action of cortisol ” this is why elite athletes (my area of expertise) ” don’t eat carbs in the evening. They need to be able to get up and get on with their training without feeling sluggish.

    I reckon if it’s good enough for the world’s top athletes, it’s good enough for me, right?

  15. Dr Vince Edghill 14 September 2008 at 2:28 pm #

    As a physician with type 2 diabetes and a committed low carb practitioner of some 10 years ,spending lots of my days preaching it’s merits and countering the politically correct low fat / high carb nonsense I side fully with David Wilson.The bizarre doctrine promulgated by every diabetic association that “all experts agree that a high carbohydrate diet is the best diet for diabetes” appears to be slowly unraveling.It is easy for us with diabetes to become emotional surrounding this advice .As a doctor I see the ravages of this advice every day and continue to be amazed at the folly of it.Indeed from my own wide experience both personally and clinically were it’s impact on so many lives( worldwide )not so tragic, one could laugh at the folly of it.Thousands of us diabetics have long discarded this silliness of high carb/low fat.It is able to be a proven nonsense with the first blood glucose test you do following your first eggs and mushroom and tomato breakfast rather than the carb. riot recommended by the various diabetic educators ,themselves,almost never diabetics.(Maybe it would help if their job became designated,I mean, there are so many of us around now.)Although I live and work in Australia,I hail from Barbados, which apart from being a small and rather exotic little island,has been dubbed by a visiting American Dr. as the amputation capital of the world.My adopted half brother back home who is a type 2 diabetic (complete with CABG and amputated leg) had me to a soul food lunch not long ago.A bowl of soup/stew of breadfruit,yam,sweet potato (plus a bit of fatted calf as I’d bin away too long,man.)But he reckoned that he had the food sort of right because “starches are good but you got to watch out for that fat”).So,there’s a bit of emotion for you.But it will not win the day.The fear of saturated fat is massively entrenched and only slowly will good studies chip away.The recent article by Shai et. al out of Israel is another chip.Although not very relevant to diabetes per se,it ends up by calmly suggesting that low carb needs to be seen as another pathway .At least it may (I nearly said will there) cause some of the genuine thinkers in nutrition to reconsider ,rather than to trot out the cliche that there are no long term studies on low carb.( delete all of the earlier studies of indigenous peoples etc. etc)
    John Briffa,I think you are another important chip.


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