The study is the first to show how meal timing affects 24-hour energy metabolism; when food intake and meal frequency are matched. They suspect that a majority of people may find meal timing strategies helpful for losing weight; or to maintain their weight since these strategies naturally appear to curb appetite, which may help people eat less.”
Courtney M. Peterson, Ph.D., one of the study’s authors and an assistant professor; Department of Nutrition Sciences, UAB Peterson and her colleagues also reported that meal timing strategies; may help people burn more fat on average during a 24-hour period. 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.
Meal timing strategies
For the study, researchers enrolled 11 adult men and women who had excess weight. Participants recruited between November 2014 and August 2016. Adults, in general good health; age 20 to 45 years old eligible to participate if they had a body mass index between 25 and 35 kg/m2 (inclusive), body weight between 68 and 100 kg; a regular bedtime between 9:30 p.m. and 12 a.m., and for women, a regular menstrual cycle.
Participants tried two different meal timing strategies in random order: a control 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 six-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 four days in a row. On the fourth day, researchers measured the metabolism of participants by placing them in a respiratory chamber; a room-like device where researchers measured how many calories, carbohydrates, fat and protein burned. Researchers also measured the appetite levels of participants; every three hours while awake, as well as hunger hormones in the morning and evening.
Aspects of appetite
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. “By testing eTRF, they able to kill two birds with one stone,” said Peterson, adding that the researcher able to gain some insight into daily intermittent fasting (time restricted-feeding), as well as meal timing strategies that involve eating earlier in the daytime to be in sync with circadian rhythms.
The researchers believe that these two broader classes of meal timing strategies may have similar benefits to eTRF. Peterson, who serves as a scientist with the UAB Nutrition Obesity Research Center, and colleagues say prior research has been conflicted on whether meal timing strategies help with weight loss by helping people burn more calories or by lowering appetite.