The first human test of early time-restricted feeding is showing that this meal-timing strategy may help reduce swings in hunger and altered fat- and carbohydrate-burning patterns.
In early time-restricted feeding (eTRF), individuals eat their last meal by the mid-afternoon and do not eat again until breakfast the next morning. In a new study presented at ObesityWeek 2016, researchers found that eating only during a much smaller window of time than people are typically used to may help with weight loss.
Courtney Peterson, PhD, MSc, assistant professor in the department of nutrition sciences at the University of Alabama at Birmingham, and colleagues found that eating between 8 am and 2 pm followed by an 18-hour daily fast kept appetite levels more even throughout the day compared with eating between 8 am and 8 pm. The findings suggest that eating a very early dinner, or even skipping dinner, may have some benefits for losing weight. The body has an internal clock, and many aspects of metabolism are at their optimal functioning in the morning. It is theorized that eating in alignment with the body’s circadian clock by eating earlier in the day may positively influence health.
The current study of eTRF suggests this eating pattern may affect metabolism. This first test of eTRF in humans follows rodent studies of this approach to weight loss, which previously found that eTRF reduced fat mass and decreased the risk of chronic diseases in rodents.
Dr Peterson and colleagues conducted a study with 11 men and women with excess weight. The study participants had a BMI between 25 and35 kg/m2 (mean BMI: 30.1 kg/m2) and were between aged 20 to 45 years (mean age: 32 years). All participants were followed over 4 days of eating between 8 am and 2pm (eTRF), and 4 days of eating between 8 am and 8 pm (average feeding for Americans). The researchers then tested the impact of eTRF on calories burned, fat burned, and appetite.
To eliminate subjectivity, the researchers had all participants try both eating schedules, consuming the same number of calories both times, and completing rigorous testing under supervision. The researchers found that although eTRF did not affect how many calories participants burned, it reduced daily hunger swings and increased fat burning during several hours at night. It also improved metabolic flexibility.