Why When You Eat May Be as Important as What You Eat
If you’re struggling to lose weight (and really, who isn’t?), it may be a matter of when as much as what you eat. Eating at the “right” time of day may be more key to weight loss than the number of calories you consume, a new study suggests.
Researchers at the University of Texas Southwestern Medical Center fed five groups of mice a diet about 30 percent lower in calories than their usual diet, but found that only those who ate during their normal active feeding time (at night for mice) lost weight. Those that ate at the wrong time (during the day for mice) gained weight, even though they consumed 30 percent fewer calories than normal.
The findings may indicate that, for humans as well as mice, dieting may only be effective if we eat at the “right” time (for humans, during the day, when we are normally awake and active) rather than the “wrong” time (for us, at night, when we would normally be sleeping), says Joseph S. Takahashi, chairman of neuroscience at UT Southwestern’s Peter O’Donnell Jr. Brain Institute and investigator with the Howard Hughes Medical Institute, who led the study published in Cell Metabolism.
“The time at which you eat may be as important as what you eat,” Takahashi tells Healthy Eats.
The time we eat may affect our circadian rhythms and the way our livers metabolize nutrients, he explains, adding that previous studies have also provided evidence that, for humans, rethinking the calorie content of our three meals a day may be beneficial for weight loss.
“In these experiments a comparison was made between having a heavy meal at breakfast and a light meal at dinner versus a light breakfast and a heavy dinner,” Takahashi says. “Those people who consumed the most calories at breakfast lost more weight.”
So maybe cut down on the night eating then? Unless you’re a mouse.
Amy Reiter is a writer and editor based in New York. Her work has appeared in publications including The Los Angeles Times, The New York Times, The Washington Post, The Daily Beast, Glamour and Marie Claire, as well as Salon, where she was a longtime editor and senior writer. In addition to contributing to Healthy Eats, she blogs for Food Network’s FN Dish.
*This article was written and/or reviewed by an independent registered dietitian nutritionist.