Diabetes – a Lens for our Health Woes

Let us start with the premise that a fat, inactive group of people has poorer wellbeing than a thin, active one and it is desirable to try and move people from the former to the latter. Prevention of chronic disease and improving resilience of the population should reduce pressure on overstretched health service worldwide. Diabetes is a classic example, with NICE continuing to recommend a diet consisting of 50% carbohydrates for a disease caused by insulin resistance! It seems illogical not to have carbohydrate restriction as first line management for diabetes.[1]

We also need to clear the confusion around inactivity and obesity. Firstly, becoming active will not make you become thin. More activity makes you hungrier and if you diet you become more sedentary.[2] To state that obesity is merely a function of calories in and calories out is unhelpful when trying to bring about behaviour change in a species that has evolved to deal with under supply of calories.[3] The problem is not obesity per se, but fat storage. The human race has genetically evolved to store fat. If you were someone who could store fat efficiently, then you would survive wars, famines, droughts, and plagues, and pass those genes on to the next generation. In the last 60 years or so the food industry has worked out how to produce loads of carbohydrate rich foods at immense profit. We still store fat very efficiently so this has created the obesity epidemic. One of the reasons that NICE still recommends a high carbohydrate diet is that fats in particular are energy dense foodstuffs, but this also presumes rather illogically that humans will consume the same weight of food irrespective of calories!

The food industry is cunning, however, and is now trying to blame simple sugars solely for this problem so diet drinks are now literally becoming the flavour of the month. The problem is that all carbohydrates are problematic, even the so called ‘healthy stuff’, such as potatoes, rice, bread, pasta, etc. Carbohydrates are the only component of food to stimulate an insulin response leading to conversion to free fatty acids and then triglycerides – within 2-3 hours the individual is hungry again. Having one of the most sedentary populations in the world and our grazing culture creates the perfect storm.

I should say at this point that we are a divided country and if you are active in the first place then it probably doesn’t matter very much what you eat as you merely use it as fuel.

There is also the commonly held belief that fat consumption clogs up your arteries, but several studies, including meta-analyses, have consistently failed to show reduction in levels of heart disease with low fat diets.[4]

Finally just to really push the boat out one should question the mantra of five (fruit and vegetables) a day. Although studies have shown some reduction in cardiovascular disease, there is little evidence for the reduction of rates of cancer.[5] My suspicion for the mixed message is that fruit and vegetables are not the same. Five 100g portions of random fruits will give you around 380 calories. Five 100g portions of vegetables will give you around 80 calories. So not only an insulin response and fat storage with fruit, but also an extra 300 calories.

Many people engage with activity to lose weight and disengage because their primary motive is not achieved. Inactivity has been shown to be the single worst thing you can do to yourself. A massive study of 364,000 patients over 12 years published earlier this year showed it is twice as likely to kill you as obesity.[6]

So the bottom line is get active but be aware that is so much easier to do that if you are thin. To do that, get rid of the carbs!

— Dr Ewan Hamnett, Birmingham’s Champion for Physical Activity, Board Member UK Active

References:

  1. Feinman RD, Pogozelski WK, Astrup A, et al. Dietary carbohydrate restriction as the first approach in diabetes management: Critical review and evidence base. Nutrition. 2015; 31(1): 1-13.
  2. Malhotra A, Noakes T, Phinney S. Its time to bust the myth that you can outrun a bad diet. Br J Sports Med. 2015. [ePub].
  3. Ludwig DS. Increasing adiposity. Consequence or cause of overeating. JAMA. 2014; 311(21): 2167-8.
  4. Siri-Tarino PW, Sun Q, Hu FB, Krauss RM. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Am J Clin Nutr. 2010; 91: 535-46.
  5. Boffetta P, Couto E, Wichmann J, et al. Fruit and vegetable intake and overall cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC). J Natl Cancer Inst. 2010; 102(8): 529-37.
  6. Ekelund U, Ward HA, Norat T, et al. Physical activity and all-cause mortality across levels of overall and abdominal adiposity in European men and women: the European Prospective Investigation into Cancer and Nutrition Study (EPIC). Am J Clin Nutr. 2015. [ePub].
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3 thoughts on “Diabetes – a Lens for our Health Woes”

  1. Dr Hamnett makes some excellent points. However I think in addition to reducing overall portion size, shift in food groups needs to be individually tailored. Many people can cut their fat intake without being left feeling hungry. However if they reduce the amount of complex carbohydrate at meal times, the resulting dip in blood sugar levels makes them hungry between meals. The food available to us between meals is usually high fat and high sugar. I don’t dispute that cutting carbohydrate intake leads to weight loss for some people. But I would also like to point out that weight maintenance and weight loss may require a different dietary balance in one individual.

  2. I think it is worth highlighting the biased and inaccurate nature of the information around diet and diabetes in this blog.
    Firstly, the references selected around carbohydrate are all from low-carb, high-fat diet proponents and don’t represent a balanced, systematic approach to appraising the evidence.
    Secondly, several systematic reviews, including the latest one by van Wyk et al 2015, conclude weight loss as the key factor in improving blood glucose control in Type 2 diabetes rather than the differences in carbohydrate intake: http://onlinelibrary.wiley.com/doi/10.1111/dme.12964/abstract
    Current guidelines do NOT recommend a diet consisting of 50% from carbohydrates. Instead, an individualised approach is recommended: https://www.diabetes.org.uk/About_us/What-we-say/Food-nutrition-lifestyle/Evidence-based-nutrition-guidelines-for-the-prevention-and-management-of-diabetes-May-2011/
    Finally, the most recent policy statement from Diabetes UK and The British Dietetic Association’s Diabetes Specialist Group still recommends reducing saturated fat and replacing this with unsaturated fats: https://www.bda.uk.com/news/view?id=95&x%5B0%5D=news/list
    The evidence for exercising in diabetes suggests an improvement in HbA1c (a measure of long-term diabetes control) can be obtained irrespective of any associated weight loss…

  3. Dear Richard,
    I am afraid that whole field of diet advice is filled by unfounded statements and the historical record of the diet advice is a total failure. You did not mentioned the recent (well, recent on my scale) advice to eat more orange\red fruits, not to eat the cholesterol-rich food, not to eat animal fat, the promotion of margarines as low-cholesterol, non-animal fat, etc. 100 years ago the fresh cucumbers were considered unhealthy thanks to medical advice, and so on.
    I am not trying to repeat the verdict by J P Ioannidis to the field, but I invite to think more about how quick we have to be in promoting our research based knowledge to the action in population?

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