While intermittent fasting may be taking over the C-suite, a new study published in Annals of Internal Medicine suggests the popular diet trend produces similar weight-loss results as traditional calorie counting.
“There were no long-term studies that looked at the way people usually do time-restricted eating with an eight-hour window [of restricted eating],” says Krista A. Varady, Ph.D., study author and professor of nutrition at the University of Illinois Chicago. “We wanted to see if weight loss would be better with time-restricted eating versus traditional calorie counting, and it wasn’t.”
The study, which included 90 racially diverse adults with obesity from the Greater Chicago area, randomly assigned participants into one of three groups:
- Eight-hour time-restricted eating, wherein participants could eat only between noon to 8 p.m., without calorie counting
- Calorie restriction, wherein participants reduced 25% of their calories daily
- No change in their calorie consumption, with meals taking place across 10 hours or more throughout the day.
Participants in the time-restricted eating and calorie restriction groups met regularly with a dietitian. Researchers from the University of Illinois Chicago found that participants in the time-restricted eating group ate 425 fewer calories than the control group and lost roughly 10 more pounds than the control group after one year.
However, participants in the calorie-restricted group ate 405 fewer calories per day and lost about 12 more pounds after one year. Participants in both groups demonstrated strong adherence to their respective interventions.
Researchers believe that access to dietitians likely helped participants in the restricted eating group make healthier food choices and that the study results can help guide clinical decision-making by taking into consideration an individual’s preferences rather than simply choosing a diet that may be deemed more effective. However, further research is needed to determine who would most benefit from each of these interventions.
“People can count time instead of counting calories,” says Varady. “The diet is free as well and you don’t have to buy expensive food products, which makes it accessible. For people who got burned out doing calorie restriction, this is a viable option.”