Low carb diets for diabetes – not sustainable? Really effective? Low carb diets for weight loss in the general population are supremely popular, but claims abound that they’re really no more effective than any other diet that results in a calorie reduction, despite reasonably impressive results from those who take on the diet.

For patients with diabetes, it’s a different matter, and while simple calorie reduction will have an impact on the overweight state many of this cohort are in, you haven’t necessarily addressed their sugar intake, which is undoubtedly an issue for diabetes patients. It’s perfectly feasible to reduce calories through fats, while still keeping carbohydrates at a level that’s probably too high. And if you’re going to address diabetes through dietary intervention alone, then you need to affect a person’s carb intake, so say the proponents of a low carb diet.

There is another issue to consider, alongside the total grams of carb in a diet. Simply lowering carbohydrates isn’t necessarily enough – you need to take into account the glycaemic index (GI), or in other words, how quickly it raises blood sugar levels. High GI foods – white bread, the majority of cereals, among others – cause quick spikes in blood sugar. Not ideal for diabetes sufferers. NICE guidelines recommend low GI carbohydrates – sweet potatoes, wholewheat pasta – for dietary intervention in diabetes patients.

Despite the sound theory, and the success champions of low carb, such as GP Dr David Unwin, have had with their patients, the problem is evidence. There isn’t a great deal of long-term evidence out there showing benefits of low carb over other dietary intervention. Many recent studies show similar effects for low carb-high fat vs. high carb-low fat diets. And over a prolonged period of time, the suggestion is that patients just aren’t going to be able to stick to it – most diabetes sufferers have enough of a challenge sticking to a diet that simply reduces calories, let alone one that cuts carbs out too.

Nevertheless, the low carb diet is growing in popularity. Dr Unwin discussed the issue in the House of Lords at the beginning of April, and continues to have great results with his patients using this method. But the opponents to the low carb ideal mean it would make a great debate.