Low carb diet found to lower insulin levels (go figure)

While not all dietary approaches are applicable or beneficial to everyone, there are some, I think, that generally hold true. Here’s one: if you want a long and healthy life, do what you can to ensure stability in blood sugar and insulin levels. What this means usually means in practice is the regular eating of foods which tend not to disrupt blood sugar (and therefore insulin) levels such as meat, fish, eggs, green vegetables, certain fruits (e.g. apples, berries) beans, lentils nuts and seeds.

What this diet is generally devoid of, you may notice, is foods containing refined sugar and starchy carbs such as bread, potatoes, rice, pasta and breakfast cereals. The quite ‘primal’ diet above is often dubbed a ‘low carb’ diet, on the basis that it contains considerably less carbohydrate compared than the starch-rich diet so often advocated (and eaten) these days. Some people even recommend this sort of diet for diabetics, even though carbohydrate is the specific dietary element that diabetics have difficulty handling. For more on this specific issue and the nonsensical nature of advice so often metered out to diabetics, see here and here.

Part of the rationale for a carb-controlled diet in diabetics comes from the fact that the carb one eats, the lower the blood sugar level will tend to be. And at the risk of stating the obvious, this is of clear merit for diabetics whose prime ambition might be to keep blood sugar levels under control.

However, another important part of the rationale for eating a low or lower carbohydrate diet is that it demands less insulin to be secreted by the body’s pancreas. Generally speaking, the less insulin someone secretes, the less likely they are to sufferer from ‘insulin resistance’ (when the body’s ability to respond to insulin’s blood sugar lowering effects is blunted). Also, less insulin means less likelihood that the cells in the pancreas responsible for secreting insulin ” the so-called ‘beta’ cells ” will ‘exhaust’.

Basically, the more insulin someone secretes over time, the more likely they are to suffer from a lack of insulin and/or an inability to respond to it appropriately. This is a situation many type 2 diabetics can find themselves in, particularly, logic dictates, if they eat a diet replete with carbohydrates including starchy ones.

Of course this concept of controlling carb intake is not just relevant for diabetics, but also for those who would prefer not to develop diabetes. I was therefore interested to read a recent study which tested the effects of low-carb and low fat (and higher carb) diets in a group of obese adolescents aged 12-18. This 12-week long study that these diets performed similarly well with regard to changes in measures such as body mass index and body fat percentage.

On the other hand, the low carbohydrate diet out-performed the low fat one in two critical areas. Firstly, insulin levels were lower in those eating a lower carb diet. The researchers also used an assessment known as the homeostatic model assessment (HOMA) which is used to measure the extent to which an individual is suffering from insulin resistance and beta-cell exhaustion. Here too, the low-carbers faired better.

In short, after just 3 months on a lower carb diet, adolescents saw improvements in their biochemistry which would, generally speaking, put them at reduced risk of developing type 2 diabetes over time. This evidence is in line with other research which has found that the consumption of blood sugar-disruptive disruptive carbohydrate is associated with an increased risk of diabetes.


Demol S, et al. Low-carbohydrate (low & high-fat) versus high-carbohydrate low-fat diets in the treatment of obesity in adolescents. Acta Paediatr. 2008 Sep 29. [Epub ahead of print]

17 Responses to Low carb diet found to lower insulin levels (go figure)

  1. Jennifer Eloff 17 October 2008 at 2:13 pm #

    Many years ago now, I bought into the traditional diet for people with diabetes. I was young and did not question the authorities. It was only when I myself started having weight difficulties that I found out about the low-carb diet option.

    Later, I watched how an elderly lady friend of mine with diabetes was suffering on that diet. In one short weekend at my home, her blood sugar became almost normal. However, despite that, she went back to eating high carb and low fat, because it was what was prescribed by her doctor and diabetes counselor, plus it was easier for her as that is the way she had always eaten. She had tons and tons of low fat cookbooks and diet books along those lines. She was neither skinny nor was she healthy as a result of following that diet all her adult life. In the hospital (she had frequent stays), she ate a dinner with mounds of potato, carrots, peas, small steak, big glass of orange juice and cake for dessert. Then the nurse came by and gave her a shot of insulin. Wow! Unbelievable! Diabetes is a carbohydrate intolerance disease and yet carbohydrates are encouraged but fat is vilified. Of course, it must be the fat making them sick many of them think. They think if they don’t eat fat, they will lose weight and the diabetes will be less of a problem. That must be the reasoning.

  2. Carol 17 October 2008 at 2:17 pm #

    The evidence on carbohydrate restriction and diabetes management, as well as prevention, is now so strong. It is therefore incredible that UK diabetic clinics are still advising their patients to eat ‘plenty of carbohydrates at every meal’ and with very little guidance on the source of those carbohydrates. And yet they say nutritional therapists are dangerous!

  3. Sharon du Raan 17 October 2008 at 7:24 pm #

    Over the last 7 years I have watched many diabetics try and get their insulin under control to no avail. Once they are able to understand the principle of low carbs and not low fat and less protein, the results that they have are astounding. In my practice I have some amazing examples of the use of more protein and fat in the diet having the most amazing effect. One diabetic is so stable that she is seen as the perfect example of how to manage diabetis. Her dietician is convinced she is eating high carb and low fat but her true diet is so different that the dietician would have heart failure on finding out.

    She is now advocating her eating programme to her diabetic friends and they are all looking stunning and have excellent insulin levels.

    Thank you for a wonderful information blogg.

  4. Kristine Franklin-Ross 17 October 2008 at 10:11 pm #

    My Mother followed the standard diabetes diet for over 30 years, I tried to explain to her that it wasn’t any good and explained to her about low carb eating, but, She told me that she had all the doctors looking after her and why would she listen to me.

    She had her leg removed just below the knee at age 82, the leg was in a terrible state and gave her great pain, 8 months later the other leg went the same way and my Mum couldn’t face another operation and was allowed to die.

    I just wish these people who push this high carb way of eating for diabetics could see the damage it does, mind you, they’d probably just say the patient was non compliant, no win situation.


  5. Matthew Lake 18 October 2008 at 5:00 am #

    I think most people would benefit from just eating less calories. Having your main diet consisting of vegetables, some fruits, nuts and lean meats, including fish. Moderate low GI carbs are fine, and you wont end up diabetic in the first place. I’ve been doing Calorie Restriction now for over 5.5 years and works amazingly well… Don’t think I could possibly get better insulin sensitivity 😉

  6. Hilda 18 October 2008 at 3:22 pm #

    Why doesn’t she tell the dietician what she is doing? This is the only way they will eventually change their tune. If you look at the plate or pie chart that is in the hospitals for diabetics and others it is mainly carbs for as as well as the bread, pots, pasta section, there is another section for fruit and veg which are also carbs.

  7. Susan 18 October 2008 at 5:05 pm #

    Yes this seems convincing. I’m keen to not become diabetic and and have generally given up cakes and biscuits & food with added sugar. However in practise when you want a quick lunch that satisfies and keeps you going till mid afternoon what would you have… given that a sandwich is so convenient.
    eg: would oatcakes plus an avocado, a bit of ham or chicken and salad be recommended or do oatcakes qualify as carbs?

  8. Katrina Woodrow 18 October 2008 at 7:57 pm #

    Oatcakes are still carbs but they are complex so they release sugar into the bloodstream at a slower rate.

    Because I have always had a sweet tooth I take a gymnema sylvestre tablet every morning to balance my blood sugar and support my pancreas. It has cut my sweet cravings to a degree and if I get really bad I suck it and it numbs my taste buds to the taste of sweetness for about an hour. This herb is used in India for type II diabetes.

  9. Sue 19 October 2008 at 12:05 am #

    Oatcakes are carbs. It would depend on how much carbs they have. I think Bernstein recommends about 6/7g carbs per meal??
    You’ve got to remember that you can still have carbs just a small amount.

    I also agree with Hilda that Sharon’s mum should tell her dietician as this is the only way health professionals will start learning. The dietician is under the wrong impression that Sharon’s mum is controlling her diabetes with high carb and low fat so this is good evidence for the dietician that it works!

  10. Hilda 19 October 2008 at 3:55 pm #

    Susan, As a nutritionist I tell people to have just one slice of wholemeal bread (if nothing else is around)with double the amount of normal filling. It is the protein which keeps us going and prevents hunger. I think oatcakes are OK as long as they are made with olive oil and not vegetable oil. Another problem! Eating outside the home is very difficult as carbs are everywhere.

  11. John Adler 19 October 2008 at 11:36 pm #

    Your comments on diabetes and carbs strike me as very forward-looking. What would be extremely helpful would be some concrete suggestions as to what to eat for breakfast. I tend to use muesli oats (pure and unadulterated) moistened with water and with added berries. Is this any good? If not, what do you recommend.

  12. SkepTicTacToe 20 October 2008 at 9:04 am #

    MatthewLake – CR may fit in to the overall picture, but avoiding refined carbohydrate would appear to be more pertinent to diabetes avoidance , management and (possible) cure.

    I myself follow a paleo diet. I let my hunger dictate how much I eat and when – and as such, somtimes eat only once a day (which technically constitutes a 24 hour fast).

    For most people on a diet of refined cabohydrate, they would have a lot of problems with such fasts. The gnawing hunger of a carboholic is something I remember well!

  13. Anna 21 October 2008 at 4:31 am #

    I have impaired glucose tolerance and oats raise my blood glucose higher than is healthy, whole grain or not! And oasts make my BG stay elevated too long, too.

    There is only one way I will feed anyone in my family oats, and that is whole groats (not steel cut, not rolled, and certainly not pre-cooked instant), soaked overnight in water with a bit of whey added to acidulate it and neutralize the phytic acid (and hopefully some of the other grain nasties). Then it only takes about 5-10 minutes to cook in the morning; but it’s a bit more like nutty pilaf than starchy porridge. My son has one tsp pure maple syrup and lots of grass fed butter on top (I never restrict butter). This is the only cereal served in my house, and only on weekends if I remember to soak. The rest of the week we each have 2-3 eggs cooked lightly in butter to set the whites, leaving the yolks runny. Very fast and no one gets the mid-morning hunger rumbles.

    If it were up to me, the oats wouldn’t even be in the house, but that’s our compromise. My son likes cereal now and then so whole soaked and cooked oats are my compromise on weekends. I think paleo diets are far healthier. When I bake now, I use gluten-free, non-grain coconut flour. Lotsa eggs are the key, as gluten-free flours need more binder.

  14. Hilda 21 October 2008 at 10:10 pm #

    Eating once a day will not give you all the nutrients you need. It is not all just about low carb. Most people are in fact undernourished in vitamins, minerals , antioxidants and essential fats.

  15. John 25 March 2009 at 4:04 pm #

    Why, when in discussion of the merit or otherwise of carbohydrate, is there no mention of soluble fibre?

    As for eating once a day – that just does not make sense – on two counts;
    1, It defies logic to think that so doing can lead to stable insulin and other hormone levels.
    2, If free-radicals are a by product of fueling cells with energy then the body needs a reliable source of anti-oxidants to neutralise them.


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