It’s estimated that over 400 million people around the world are living with diabetes, though that’s probably an underestimate, as almost half of all cases are undiagnosed. At the very least, 1 in 11 adults suffer from diabetes, and 90% of them have type 2 diabetes. There are several efficient drugs that can help keep type 2 diabetes under control, but it’s also known that a healthy diet and exercise can help keep the disease in check or even reverse. Now, a new study may have found a new weapon to do that: intermittent fasting.

Intermittent fasting has only recently stepped into the spotlight as a method that can tackle various diet-related diseases. There are few large-scale studies on humans, but a 2019 review found that intermittent fasting may help with problems ranging from obesity and insulin resistance to hypertension and inflammation.

Intermittent fasting comes in various forms. In some versions, you eat the same amount every day, but you restrict your eating within a few hours of the day; typically, the day is split into an 8-hour and a 16-hour interval, and you eat all your meals in the former, and never eat in the latter. Another type of intermittent fasting is when you eat normally on some days, and then less than usual on other days — this was also the case here.

The researchers conducted a 3-month study on 36 people with diabetes. They had participants eat only 840 kilocalories for 5 days (the average recommended number is around 2,000 kcal), and then eat normally for 10 days, according to the Chinese dietary guidelines. Over the course of the intervention, more than half (17/36) of those in the intermittent fasting group reversed their diabetes and were still diabetes-free after one year. In another control group, just 1 out of the 36 achieved remission.

“Type 2 diabetes is not necessarily a permanent, lifelong disease. Diabetes remission is possible if patients lose weight by changing their diet and exercise habits,” said Dongbo Liu, a researcher at the Hunan Agricultural University in Changsha, China, and one of the study authors. The researcher added that this diet can also help reduce medication cost. “Diabetes medications are costly and a barrier for many patients who are trying to effectively manage their diabetes. Our study saw medication costs decrease by 77% in people with diabetes after intermittent fasting,” Liu said.

However, other researchers noted that it’s a small-scale study, and more importantly, the people in the intermittent fasting group lost a lot of weight — something that has been linked to type 2 diabetes improvements. Participants in the intermittent fasting group lost almost 6 kg off weight on average, which makes it nigh impossible to say if it’s the intermittent fasting that’s helping or just the weight loss.

“This study reinforces the message that Type 2 diabetes is a reversible condition, and shows that remission is possible in those with diabetes of relatively long duration,” said Keith Frayn, Emeritus Professor of Human Metabolism at Green Templeton College, University of Oxford. “The use of intermittent fasting as a means of reducing body weight to induce diabetes remission is new, and may prove useful as it seems the participants found it easy to follow this strategy.  However, it seems probable that the beneficial effect on the diabetes is primarily due to the loss of weight, as has now been shown in several studies, rather than any specific effect of the intermittent fasting protocol.  A different experimental design would be needed to support any claim that intermittent fasting has beneficial effects beyond loss of body weight

It’s also important to keep in mind that you shouldn’t just do intermittent fasting willy-nilly — it’s best to consult with a specialist before embarking on anything like this.

“Although there have been studies to show low-calorie diets and low-carbohydrate diets can help people with type 2 diabetes achieve remission, this relatively small study is the first to show the use of intermittent fasting,” added Duane Mellor, Registered Dietitian and Senior Lecturer at Aston University. “As one of the best predictors of achieving remission in type 2 diabetes is weight loss, it is impossible to say if it is intermittent fasting which is helping to induce remission as it is most likely to be the result of the weight loss. If people with type 2 diabetes are thinking about changing their diet or wonder if they might be able to put their diabetes into remission, it is important that they speak to the diabetes health professional and discuss the potential effects of changing diet on their medication to minimise risks for example hypoglycaemia.”

At the end of the day, intermittent fasting or not, having a healthy diet (especially one that promotes a healthy weight) can tackle diabetes in the long term, improving overall health and reducing the need for drugs. As time passes, larger studies will no doubt shed more light on how (or if) intermittent fasting is different from other approaches.

The study was published in the Journal of Clinical Endocrinology & Metabolism.