In the United States, more than 34 million people have diabetes — the vast majority Type 2 diabetes — which arises when the body loses its sensitivity to the hormone insulin. Strict limits on carbohydrates can help get Type 2 diabetes under control, but the benefits typically wane over time, new research shows.

An analysis of 23 small trials found that low-carb diets worked better than other eating plans in helping people lose weight and send their Type 2 diabetes into remission. That was true, at least, in the first six months. By the one-year mark, most of the advantages of the low-carb lifestyle had vanished.

It’s not clear why, according to Grant Brinkworth, one of the researchers on the review. But it’s possible people had a tough time sticking with the diets.

Still, people with Type 2 diabetes might be able to kick-start some weight loss and better blood-sugar control with a low-carb diet.

“The findings of this study suggest, at least in the short term, that people with Type 2 diabetes could consider a low-carb diet as a treatment option,” said Brinkworth.