“We found that early time-restricted feeding (eTRF) increases fat oxidation for several hours at night, although the increase in total daily fat oxidation was not significant. However, eTRF did improve metabolic flexibility, which is the ability to switch between burning carbohydrates and fat. Other studies show that metabolic flexibility is impaired in insulin-resistant individuals. So since eTRF increases metabolic flexibility, this may be beneficial for health,” Dr Peterson told Endocrinology Advisor

She said eTRF does improve weight loss in rodents, but it is too early to say yet whether early time-restricted feeding will improve weight loss in humans. If eTRF does improve weight loss or fat loss in humans, it looks like eTRF would do so by reducing food intake or by increasing fat oxidation and not by increasing the number of calories burned, according to Dr Peterson. 

“The surprising thing we found is that participants were not hungrier on average on eTRF, even though we had them fast daily for 18 hours. So, we overturned the belief that fasting for a longer period each day (when the same number of total calories are eaten) intrinsically makes a person hungrier. Moreover, we found contrary to our expectation, that eTRF kept hunger levels more even throughout the day (smaller swings in hunger), which again, may provide a benefit in losing weight,” said Dr Peterson.

Dale Schoeller, PhD, a spokesperson for The Obesity Society and professor emeritus at the University of Wisconsin, said with additional research on eTRF on humans, it may be possible to create a more complete picture of whether this approach can help with combating obesity.  

“This is one of the first studies of time restricted feedings in humans and it is also a preliminary report based on the first 11 subjects of what is expected to be a larger study. Animal studies and these early data do indicate that time restricted feeding will have benefits,” Dr Schoeller told Endocrinology Advisor.

Reference

  1. Peterson C, Poggiogalle E, Hsia D, Ravussin E. Time-restricted feeding increases fat oxidation and reduces swings in appetite levels in humans. Abstract T-OR-2081. Presented at: ObesityWeek 2016; October 31-November 4, 2016; New Orleans, LA.