In recent years, there has been a wealth of research studies showing low-carb diets to be very effective for people with diabetes.
Despite the success of low-carb diets, the UK still advises people with diabetes, and the population in general to consume a low-fat diet that is much higher in carbohydrate.
As more and more research supporting low-carb diets appear, the recommendation to follow a low-fat diet is becoming more and more controversial
Low-carb research and type 2 diabetes
Research into low-carb diets in people with type 2 diabetes typically show that low-carb diets are at least as good as low-fat diets.
Low-carb diets tends to perform significantly better in terms of:
- Improved blood glucose levels (HbA1c)
- Greater rates of remission – able to control diabetes well without the need for medication
Low-carb diets are usually either as effectives, or slightly more so, than low-fat diets in terms of:
- Reduced insulin resistance
- Achieving weight loss
- Improving cholesterol levels
- Lowering blood pressure levels
A 2014 study by the Second University of Naples, showed that a low-carbohydrate Mediterranian diet produced significantly greater remission rates than a low-fat diet.
The study showed that the low-carb diet led to 14.7% of participants achieving remission in the first year and 5% achieving remission after six years.
By compariso, those following the low-fat diet had remission rates of 4.1% after the first year and 0% after six years.
When low-carb and low-fat diets have been directly compared, low-carb diets have typically outperformed the low-fat diets.
Mayer et al. (2013): A low-carb diet outperformed a low-calorie, low-fat diet that was supplemented with the weight loss drug Orlistat. The results showed similar weight loss, whereas the low-carb diet was most effective at reducing HbA1c levels and dependence on medication. 
Westman et al. (2008): A low-carb ketogenic diet was compared with a low- glycemic index diet. The low-carb group had a significantly greater reduction in HbA1c than the low-GI diet group. (17 mmol/mol compared with 6 mmol/mol). The low-carb group also showed the greatest improvements in terms of improved cholesterol levels and reduced dependency on diabetes medication. 
Low-carb research and type 1 diabetes
Whilst most research studies into low-carb and diabetes focus on type 2 diabetes, there has been a few studies that have looked at the effects of the diet for type 1 diabetes
The studies that have been carried out have been limited to one research team from the Department of Medicine at Blekingesjukhuset, in Karlsham, Sweden.
Nielsen et al. (2012): This study looked at the effects of a diet of 75g of carbohydrate per day on adults with type 1 diabetes. Whilst there was no control group involved, the study showed that those adhering to the low-carb diet had a significantly lower HbA1c (46 mmol/mol) after four years of following the diet to those that were not able to keep to the diet (57 mmol/mol).