Diets that require daily calorie cutting are hard to adhere to, and most people gain the weight back within a year. Intermittent fasting, which involves eating very little on some days and freely on others, might offer a more sustainable alternative. A recent study found that fasting three nonconsecutive days per week promoted more weight loss than daily calorie restriction as part of a comprehensive weight loss program.

Researchers assigned 165 adults aged 18 to 60 with a body mass index between 27 and 46 to one of two diet plans. One group followed a 4:3 intermittent fasting schedule, eating freely on four days of the week and cutting calories by 80% on three nonconsecutive days each week. The second group followed a daily calorie restriction (about 34% less than baseline needs) to match the same total weekly calorie reduction. Both groups also participated in a year-long behavioral weight loss program that included group support and a goal of 300 minutes of moderate exercise weekly.

After 12 months, participants in the intermittent fasting group lost roughly 6.4 pounds more, on average, than those in the daily calorie restriction group. Just over three-fourths of participants completed the study. The difference in weight loss between the two groups was small but statistically meaningful.

These findings suggest that intermittent fasting offers a modest advantage over daily calorie restriction for people trying to lose weight, especially when paired with regular exercise and behavioral support. Learn more about the health benefits of intermittent fasting in this clip featuring Dr. Mark Mattson.