Where weight and fat loss is concerned, I favour a relatively low-carbohydrate, high-protein diet on the basis that such diets generally outperform low-fat, carb-rich diets traditionally advocated for weight loss. A lower-carb diet I think may have particular advantages for diabetics because, well, they have difficulty handling carbohydrate as a result of impaired insulin function (insulin resistance) and/or insufficient insulin.
There is a certain logic to the notion that diabetics should be careful consuming the very food type (carbohydrate) they have difficulty dealing with. However, not everyone agrees. You can see here how Diabetes UK (the leading diabetes charity in the UK) specifically recommends against carbohydrate restriction on the basis that:
• glucose from carbohydrate is essential to the body, especially the brain
• high fibre carbohydrates, such as wholegrains and fruit, also play an important role in the health of the gut
• some carbohydrates may help you to feel fuller for longer after eating
However, glucose can be made from other elements of the diet (e.g. protein) which makes the absolute requirement for carbohydrate none at all. Also, wholegrains are generally rich in insoluble fibre which has been shown to be quite irritant to the gut compared to soluble fibre found plentifully in fruits and vegetables. But if diabetics are looking for a heathy source of fibre, why not point them to green veg, say, rather than carb-loaded fruit. And it might be true that carbohydrates can help people feel fuller for longer, but protein has been found to be the most sating macronutrient and doesn’t cause wild swings in blood sugar levels (as many wholegrains do) either.
Getting back to weight loss, it appears that aerobic exercise is not particularly effective here (see here for more about this). That is not to say that aerobic exercise is a waste of time – it most certainly is not in my opinion (it just does not do much to shift surplus pounds).
In recent years there has been increasing interest in the idea that resistance exercise (e.g. weight training) can help fat loss and improve body composition. See here for a previous post about a relevant study.
I was interested to read about a recent study in which resistance exercise was tried in a group of obese type 2 diabetics [1]. Individuals either performed resistance exercise (3 days a week) or no exercise for 16 weeks. Each of these groups were further subdivided into groups eating either a conventional high-carbohydrate diet, or a lower-carb, higher protein diet. The make-up of these diets was as follows:
Conventional diet carb/protein/fat: 53/19/26
Higher protein diet carb/protein/fat: 43/33/22
The diets were ‘energy-restricted’ (about 1400 and 1700 calories a day for women and men respectively).
So, in effect, this study had four groups:
1. Conventional diet no exercise
2. Conventional diet plus resistance exercise
3. Higher protein diet no exercise
4. Higher protein diet plus resistance exercise
The participants were assessed in a variety of ways including weight loss, fat mass loss and waist circumference.
Overall, the group eating higher protein lost more weight and fat and saw greater reductions in their waist circumference too. However, these differences were much more marked when comparing the groups who were exercising.
Weight loss for exercisers in the conventional and high protein groups was an average of 10.5 and 13.8 kg respectively
Fat loss for exercisers in the conventional and high protein groups was an average of 7.9 and 11.1 kg respectively
Waist circumference reduction for exercisers in the conventional and high protein groups was an average of 11.3 and 13.7 cm respectively
Looking at the results as a whole, it’s clear that the group that did the best with regard to these measurements was the one eating less carb, more protein, with resistance exercise on top.
References:
1. Wycherley TP, et al. A High Protein Diet With Resistance Exercise Training Improves Weight Loss And Body Composition In Overweight And Obese Patients With Type 2 Diabetes. Diabetes Care 11th February 2010 [epub ahead of print publication]
