Eating Earlier Promotes Weight Loss Through Decreasing the Appetite

Eating earlier in the day decreases appetite and can promote weight loss, according to results of a new trial.

It is well known that aligning eating times with circadian rhythms improves weight loss. Yet it is currently unknown whether weight loss occurs because of increased energy expenditure or decreased food intake.

This new study is the first randomized trial to examine how meal timing affects 24-hour energy metabolism when food intake and meal frequency are matched.

To conduct the trial, the researchers recruited 11 adults with overweight. For 4 days, the participants adhered to both early time-restricted feeding (eTRF), which was defined as eating from 8 a.m. to 2 p.m., and a control schedule, which was defined as eating from 8 a.m. to 8 p.m.

The researchers used whole-room indirect calorimetry and assessed appetite and metabolic hormones to measure 24‐hour energy expenditure and substrate oxidation.

Results of the analysis showed that eTRF did not affect 24-hour energy expenditure. Though, eTRF decreased mean ghrelin levels, made hunger more even-keeled, and tended to increase fullness and decrease the desire to eat. In addition, eTRF increased metabolic flexibility and decreased the 24-hour nonprotein respiratory quotient.

“Meal‐timing interventions facilitate weight loss primarily by decreasing appetite rather than by increasing energy expenditure,” the researchers concluded. “eTRF may also increase fat loss by increasing fat oxidation.”

—Amanda Balbi

Reference:

Ravussin E, Beyl RA, Poggiogalle E, Hsia DS, Peterson CM. Early time‐restricted feeding reduces appetite and increases fat oxidation but does not affect energy expenditure in humans [published online July 24, 2019]. Obesity. https://doi.org/10.1002/oby.22518.