Time-restricted eating, though trendy, may not be the magic weight-loss strategy people think. A new study suggests when you eat doesn’t really matter. Eating fewer calories is still your best bet for weight loss.
Time-restricted eating, also known as intermittent fasting, is a popular weight-loss approach where eating is limited to a period of time during the day, generally four to eight hours. Studies of its effectiveness have yielded mixed results, and no study had looked at what happened if dieters restricted the number of calories eaten when eating was allowed. This meant it wasn’t known if it was that people ate fewer calories because of time-restricted eating or if the time of day they ate made a difference.
Researchers at Johns Hopkins University in Baltimore were curious as to whether when a person eats during the day has an effect of how the body uses and stores calories so they developed a study to track what happens when calorie intake is concentrated in the early part of the day versus spread out over 12 hours during the day.
Does restricting eating to certain hours of the day contribute directly to weight loss?
Each person’s weight and blood pressure were noted at the beginning of the study and on three other occasions at four-week intervals for 12 weeks. The same pre-prepared, nutritious meals provided by the study were eaten by all participants.
People in both groups lost weight and had lower blood pressure regardless of their eating regimen.
“We thought that the time-restricted group would lose more weight,” said study author, Nisa M. Maruthur, in a statement. “Yet that didn't happen. We did not see any difference in weight loss for those who ate most of their calories earlier versus later in the day. We did not see any effects on blood pressure either.”
Time-restricted eating might be useful for helping someone eat less food, and therefore fewer calories, but it doesn’t seem that restricting eating to certain hours of the day contributes directly to weight loss.