Intermittent fasting diets can do more than help people lose weight — they may have a medical benefit, too. A new study has found people who stuck to an intermittent fasting diet improved their symptoms of diabetes.
Fasting diets are becoming increasingly popular, and there are a few different ways to do it. These study participants followed one of the most common patterns: eating normally five days a week, and cutting back to 500 or 600 calories for two days of the week. This method is referred to as the "5:2 plan."
Some people report this method is easier to follow, especially if the two low-calorie days are nonconsecutive.
A team in Australia tested the idea on overweight people with type 2 diabetes.
They recruited 137 middle-aged, obese volunteers with type 2 diabetes and randomly assigned them either to a low-calorie diet they had to follow every day, or an intermittent fasting diet.
Both groups lost a significant amount of weight after three months of both diets, and most kept it off for at least a year. Some continued losing weight.
The people who dieted every day lost an average of 11 pounds and those who did the intermittent fasting lost an average of 15 pounds, a difference the researchers said was not statistically significant
Both also had better control of their blood sugar, as measured by hemoglobin A1c — a test for average blood sugar levels over the previous few months.
That's not a surprise: Losing weight can improve symptoms of diabetes, as well as lower blood pressure and cholesterol.
Neither diet appeared to be better for weight loss, Dr. Peter Clifton, of the University of South Australia and colleagues found. But people found the intermittent fasting diet easier to follow, they reported in the Journal of the American Medical Association’s JAMA Network Open.
“The continuous energy restriction group found weight-loss maintenance more difficult because, if they were not following the diet on a daily basis, they would regain weight owing to increased energy intake,” Clifton's team wrote.
People in the intermittent fasting diet got instructions to eat 500 to 600 calories a day for two days of the week. The only other guideline on those two calorie-restrictive days was to eat at least 50 grams of protein.
According to the study, a typical “fasting day” menu might include:
- Breakfast – A piece of fruit and one tub of diet yogurt
- Lunch – One small can of tuna packed in water and one cup of salad
- Dinner – 3.5 ounces of chicken breast (about the size of a small cellphone) cooked in 1 tsp of oil, 1.5 ounces of low-carb vegetables. Diet jello was allowed.
Those on the diet-every-day plan followed a diet of 1,200 to 1,500 calories with 30 percent coming from protein, 45 percent from carbohydrate and 25 percent from fat.
“Both groups received written dietary information booklets with portion advice and sample menus; no food or meal replacements were provided,” the researchers added.
“Participants were given digital kitchen scales and encouraged to weigh foods to ensure accuracy of intake.”
But one big secret to success seemed to be frequent check-ins with dietitians every few weeks.
“Participants who attended all scheduled visits lost significantly more weight than did participants who did not,” the researchers wrote.