Intermittent Fasting Gets New Boost in Latest Research
Researchers have discovered that meal timing strategies such as intermittent fasting help people lose weight by lowering appetite rather than burning more calories, according to a new report which gives more credence to the practice of intermittent fasting.
The study is the first to show how meal timing affects 24-hour energy metabolism when food intake and meal frequency are matched.
“Coordinating meals with circadian rhythms, or your body’s internal clock, may be a powerful strategy for reducing appetite and improving metabolic health,” said Eric Ravussin, PhD, one of the study’s authors.
Lead author Courtney M. Peterson, PhD said: “We 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.”
Peterson and her colleagues also report that meal timing strategies may help people burn more fat on average during a 24-hour period.
Early Time-Restricted 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.
The study’s authors said, however, that the results on fat-burning are preliminary.
“Whether these strategies help people lose body fat need to be tested and confirmed in a much longer study,” said Peterson.
For the study, researchers enrolled 11 adult men and women who had excess weight.
Adults, in general good health, aged 20-to-45-years old were 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.
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 8:00 a.m. and dinner at 8:00 p.m. and an eTRF schedule where participants ate three meals over a six-hour period with breakfast at 8:00 a.m. and dinner at 2:00 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 were burned.
Researchers also measured the appetite levels of participants every three 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.