Updated 10 June 2019

Low-carb diet helps obese diabetics

Sticking to a low-carbohydrate diet with some limits of calories has long-term benefits on body weight and blood sugar levels, says a new study from Sweden, but a leading diabetes charity advises against following such a diet.

It is well established that some type 2 diabetics can achieve dietary control of their condition without the need for medication. And this new Swedish study adds to this by suggesting that the low-carb diet may be one such effective approach.

The new research study

The new study, published in the open access journal Nutrition and Metabolism (Vol. 3, number 22), adds to earlier research by the same scientists that obese people with type 2 diabetes could improve body weight and blood sugar levels over a six-month period by sticking to the low-carbohydrate diet.

And further follow-up shows that sticking to the diet for 22 months continued to provide benefits to the subjects, and “is an effective tool in the management in motivated obese patients with type 2 diabetes.”

Dr Jorgen Nielsen and Dr Eva Joensson from Blekingesjukhuset, Karlshamm in Sweden, recruited 31 obese type 2 diabetics (average weight at baseline 100,6kg, BMI 36,1kg per sq.m) and assigned 16 to the low-carbohydrate diet (20 percent carbs) and 15 continued to eat their normal diet (55 to 60 percent carbs). Both diets were equal in calories (1800kcal for men, 1600kcal for women).

After six months, subjects eating the low-carb diet reported an average weight loss of 11,4kg and a reduction of BMI of 4,1kg per sq.m. Subjects eating the normal diet reported weight loss of about 3,5kg.

Improvements over six months

Additionally, when the researchers measured blood levels of haemoglobin A1c (HbA1c), the form of haemoglobin usually used to follow plasma glucose concentrations over time, they found that the low-carb diet led to improvements over six months, and these improvements continued for the two years of study.

HbA1c levels for the low-carb diet fell from the starting value of eight percent to 6,6 percent after six months, and stayed almost constant at 6,9 percent after 22 months. For the normal diet, HbA1c levels fell by 0,9 percent.

A 20 percent carbohydrate diet with some calorific restriction to obese patients with type 2 diabetes had lasting effects on bodyweight and glycaemic control, said Nielsen and Joensson.

The weight reduction observed was attributed to the reduction in calories.

“Intentional weight loss in type 2 diabetes patients is association with a reduced mortality of 30 to 40 percent. For the average patient, each kilogram weight loss is associated with three to four months prolonged survival making it likely that the patients described here have achieved a survival benefit,” said Nielsen and Joensson.

Low-carb diets not recommended

However, Roopinder Braar, care advisor for British charity Diabetes UK, told that, while the study confirmed the benefit of weight loss in obese people with diabetes on their diabetes control and general health, the charity would not recommend low-carbohydrate diets for weight loss.

“Studies have shown that a healthy diet combined with physical activity is best for successful weight loss and is more effective than if you simply diet or exercise alone.

“It is a common myth that you should cut out starchy foods like bread and potatoes to lose weight.

“Reducing total carbohydrate to just 20 percent of total daily energy means that a greater proportion of your calories will come from fat and protein and the diet may be low in fruit and vegetables. A diet high in fat and low in fruit and vegetables is linked to heart disease.

"It is important that anyone with diabetes, who is trying to lose weight, should discuss it with their diabetes team who will advise them on how to lose weight safely,” said Braar.

Source: Decision News Media

Read more:

Diabetes Centre

Obesity and diabetes: Solutions


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