A study published in the journal Clinical Nutrition found that people who follow intermittent fasting lose about the same amount of weight as those who count calories, but report feeling less burdened by food-related decisions along the way. The findings may carry particular weight for so-called yo-yo dieters, people who cycle repeatedly from one diet to the next without long-term success.
According to a report by Healthline, the study analyzed data from more than 200 people with obesity. Participants were divided into three groups: one following intermittent fasting, one tracking traditional calorie intake, and one eating a standard balanced diet with no restrictions. Those in the calorie-counting group were asked to eat 70% of their usual intake. Those in the fasting group ate only between 8 a.m. and 12 p.m., then fasted for 20 hours. That cycle repeated three times a week on non-consecutive days.
Both the fasting group and the calorie-counting group lost roughly the same amount of weight. But the fasting group reported something the other group did not. They said they felt they did not need to make major changes to their eating behaviors, such as monitoring overeating or counting calories, in order to lose weight.
Lead study author Leonie Heilbronn, a professor and clinical research scientist in the School of Medicine at Adelaide University in Australia, pointed to the importance of that finding. "Previous research shows that people who improve their relationship with food and gain better control over cravings lose more weight — regardless of the specific diet they undertake," Heilbronn said.
The psychological dimension of dieting is something nutrition professionals have long observed. Monique Richard, a registered dietitian nutritionist and owner of Nutrition-In-Sight who was not involved in the study, described a pattern she sees in chronic dieters. "Many chronic dieters become trapped in a cycle of constantly tracking, counting, restricting, and thinking about food," Richard said. She added that a structured eating window may help some people. "If a structured eating window helps simplify decisions and reduce decision fatigue, that may improve long-term adherence for some people," Richard told Healthline.
Intermittent fasting has grown in popularity over the past several years. One common approach is the 16/8 method, where a person eats during an 8-hour window and fasts for the remaining 16 hours. The version tested in this study was more compressed, limiting food to a 4-hour morning window on alternating days.
The study's findings are notable for the yo-yo dieting population specifically. People who have struggled to maintain any single diet long-term may find a time-restricted eating schedule easier to follow than daily calorie tracking, based on what participants reported. The study was published on July 16 in Clinical Nutrition.