Meal-timing strategies appear to lower appetite and improve fat burning
Researchers at the University of Alabama at Birmingham have discovered that meal timing strategies—like intermittent fasting or eating earlier in the daytime—appear to help people lose weight. This approach was also shown to lower appetite rather than burn more calories.
The study is the first to show how meal timing affects 24-hour energy metabolism when food intake and meal frequency are matched.
Early Time-Restricting Feeding (eTRF)—a form of daily intermittent fasting where dinner is eaten in the afternoon—helped to improve people’s ability to switch between burning carbohydrates for energy to burning fat for energy, an aspect of metabolism known as metabolic flexibility.
Participants in the study tried two different meal timing strategies in random order: a controlled schedule where participants ate three meals during a 12-hour period with breakfast at 8 a.m. and dinner at 8 p.m. and an eTRF schedule where participants ate three meals over a 6-hour period with breakfast at 8 a.m. and dinner at 2 p.m. The same amounts and types of foods were consumed on both schedules. Fasting periods for the control schedule included 12 hours per day, while the eTRF schedule involved fasting for 18 hours per day.
Study participants followed the different schedules for 4 days in a row. On the fourth day, researchers measured the metabolism of participants by placing them in a respiratory chamber where researchers measured how many calories, carbohydrates, fat, and protein were burned. Researchers also measured the appetite levels of participants every 3 hours while they were awake, as well as hunger hormones in the morning and evening.
Although eTRF did not significantly affect how many calories participants burned, the researchers found that eTRF did lower levels of the hunger hormone ghrelin and improved some aspects of appetite. It also increased fat-burning over the 24-hour day.