Intermittent Fasting-Style Diet May Put Diabetes in Remission

Nearly half of all participants who followed an intermittent calorie-restrictive diet for three months achieved diabetes remission and no longer had to take their diabetes medications, according to a small new study from researchers in China.

Just as remarkable, those individuals were able to maintain that remission and remain medication-free at the one-year mark, per the findings, published in the Journal of Clinical Endocrinology and Metabolism.

This study shows that type 2 diabetes is not necessarily a permanent, lifelong disease, says coauthor Dongbo Liu, PhD, a researcher at Hunan Agricultural University in Changsha, China. “Diabetes remission is possible if patients lose weight by changing their diet and exercise habits,” he says.

Intermittent Fasting Can Mean Restricting Calories and Eating Only During Certain Hours of the Day

Intermittent fasting (IF) refers to any eating schedule that alternates periods of going without food (fasting) with meals. There are many different types of plans, including those that restrict calories for only certain hours of each day or certain days of the week. Because this type of diet has become an increasingly popular way to lose weight and has shown to help people reduce their risk of heart disease and diabetes, researchers decided to examine the impact of a very specialized type of IF diet on people who already have diabetes.

However, in this study, participants in the intervention group didn’t completely fast or even restrict the time of day they ate their meals. Instead, they intermittently restricted calories and followed a specific diet.

5 Days of Restricting Calories, 10 Days of Eating Normally

Investigators recruited 72 participants between 38 and 72 years old who had been living with type 2 diabetes anywhere from 1 to 11 years and used anti-diabetic drugs or insulin injections to manage the condition. Two-thirds were men, and the body mass index (BMI) ranged from 19.1 to 30.4.

A healthy BMI is between 18 and 24.9, overweight is between 25 and 29.9, and 30 and over is considered obesity, according to the Centers for Disease Control and Prevention.

Researchers randomly placed participants into one of two groups. One group ate a modified intermittent fasting diet called the Chinese Medical Nutrition Therapy (CMNT) diet; the other group had no restrictions on what they ate.

Participants followed the 15-day cycle of the CMNT diet — five modified fasting days followed by 10 days of eating normally — for a total of six times during the three-month trial.

On the modified fasting days, subjects ate foods prepared by the scientists and included ingredients such as wheat, barley, rice, rye, and oat. The macronutrient breakdown of the CMNT diet was 46 percent carbs, 46 percent fat, and 8 percent protein, which added up to 840 calories — about one-third of the daily recommended calories for the average U.S. male.

Unlike some IF diets, participants were able to eat the prescribed foods at regular intervals: breakfast, lunch, and dinner.

Nearly Half of People Went Into Diabetes Remission

After the three months, about 86 percent of the participants (31 out of 36) in the intervention group, including those who took hypoglycemic drugs and insulin, reduced the amount of diabetes medications they were taking, according to researchers.

Out of that group, about 55 percent of participants, or 17 people, went into remission (defined as having an A1C level of less than 6.5 percent) and discontinued their anti-diabetic drugs. They then maintained those levels for at least one year, says Dr. Liu.

“These findings are pretty remarkable — more than 40 percent of the group following the diet had remission and went off their medications with just a dietary intervention, and to have those results last at least a year,” says Josh Thaler, MD, PhD, who works as an endocrinologist and associate professor of medicine at UW Medicine Diabetes Institute in Seattle. Dr. Thaler was not part of the research.

To be clear, remission isn’t a cure — it just means diabetes is temporarily in a holding pattern, and in theory it could come back, he says. “We have no cures for diabetes. Even in bariatric surgery trials, which also have remarkable ability to reduce diabetes rates, we still call it remission. We never say it ‘cured’ diabetes,” says Thaler.

The Study Has Some Limitations

While the findings are impressive, there are a few things to keep in mind when evaluating the study, Thaler says. For starters, the study was small. “Even though they screened a lot of patients, they only ended up with 36 people in the intervention group,” says Thaler.

Plus, he adds, one could argue that although all the people had diabetes, on average they may not be representative of the overall type 2 diabetes population. “Most people in the study had mild or moderate diabetes at the start of the trial. On average, their A1C was already pretty close to goal (with their medications). So their diabetes was pretty well controlled, and only about 17 to 20 percent were on insulin. Also, the weight range of the participants was lower than what is typically seen in people with T2D,” he says.

Some of the People Who Experienced Remission Had Diabetes for Over 6 Years

This study disproved the conventional view that only people who’ve lived with diabetes for less than six years can achieve remission. “Sixty-five percent of the participants achieving diabetes remission in this study had a diabetes duration between 6 and 11 years,” says Liu.

In general, it’s true that people who’ve had diabetes for a long period of time may find it harder to experience remission, agrees Thaler. “These people tend to have more advanced disease and therefore tend to be on more meds, possibly on insulin, possibly having complications by then, and therefore it may be more difficult to have control at that point,” he says.

Participants in the Study Lost Close to 10 Percent of Their Body Weight in Just 3 Months

Could these results be duplicated in the real world? That’s doubtful, says Thaler, given how much weight the subjects lost.

The group that ate the CMNT diet went from an average of about 148 pounds to 135 pounds — and kept the weight off even after a year. “That’s almost 10 percent of their body weight. This is pretty dramatic, and it’s surprising that it could be achieved by just cutting calories 5 days out of 15 over a three-month period,” Thaler says.

“I have plenty of patients who are trying different kinds of intermittent fasting, but even the successful ones don’t see this level of weight loss and this fast.”

Even good medications don’t help people shed 10 percent of their BMI at three months, says Thaler. That’s why when a medication shows that it can help people achieve 5 to 8 percent body weight loss, the medical community gets excited, he points out.

Studies with the most intensive interventions are considered a success when they see weight loss in the 5 to 7 percent range, and often those people have regained some of the weight by a year, he says.

“These patients were super-compliant and kept staying compliant for a year. You just don’t often, if ever, see these kinds of results,” says Thaler. Because trial participants kept their weight off, they were able to stay off their medications, he says. “This is true with almost any weight loss intervention for diabetes: When a person loses weight, their diabetes typically improves, and if they gain the weight back, then the diabetes gets worse or comes back,” he says.