Does Meal-Timing Play a Role in Maintaining a Healthy Weight?

New research shows that meal-timing may influence the body's internal clock

There’s still a bit of a debate about whether or not meal-timing plays a role in weight regulation.

Some argue that it won’t matter when you eat, so long as you don’t consume more calories than your body needs for the day, while others contend that eating past a certain time is a surefire way to promote weight gain.

Science has yet to prove a definitive answer either way, but results from new research out of the Salk Institute for Biological Studies in San Diego add to a body of evidence that supports the latter.

According to The New York Times, the most recent study began by analyzing the details of research from 2012, which examined two different groups of mice. 

One group consumed high-fat foods whenever they wanted; the other group followed the same diet but was only allowed to eat within an eight-hour period. Neither group exercised. What scientists found: the mice who were allowed to eat whenever they pleased gained weight and began showing symptoms of diabetes, but the mice who kept their meal times within the eight-hour window didn’t gain much weight and showed no signs of metabolic issues.

With this in mind, for the new study, researchers at the Salk Institute studied groups of adult male mice who were fed one of four diets: high-fat, high-fructose, high-fat and high-sucrose, and regular mouse kibble. Each diet contained the same amount of calories. Similar to the previous study, some of the mice were allowed to eat whenever they felt like it, but others were limited to “feeding periods” of nine, 12 or 15 hours.

The experiment was conducted over the course of 38 weeks and during that time some of the “time-restricted” mice were allowed to eat whenever they wanted on weekends, while some of the non-restricted mice were given time restrictions about halfway through the study.

The results found that the mice who ate within the 12-hour period maintained healthy body weights, even if they had been allowed to “cheat” on weekends. Most of the mice who had been allowed to eat whenever they wanted became obese and “metabolically ill.”

The scientist also found that switching some of the mice from a non-restricted to a restricted eating schedule seemed to help them lose some of the weight they had gained.

What these results mean, Satchidananda Panda, an associate professor at the Salk Institute who oversaw the studies, told The New York Times, is that the times at which we consume food likely influence the “body’s internal clock.” However, it’s still not entirely understood how time-based eating patterns might prevent weight gain and related illnesses.

While these types of studies have only been performed with mice, Panda told The New York Times that he is confident that the results would also apply to humans.

What this means in terms of healthy eating habits: containing your meals to a 12-hour (or less) window each day is likely a smart weight loss and weight-maintenance strategy.