Chew on This

Learn from the mice: Eat only during a 12-hour period

If you have an overweight mouse, this study if for you. Or, if you are interested in a time-based approach to weight management, then read on. A study from the December issue of Cell Metabolism reports on how restricting eating times kept mice more svelte than their friends who chowed down during all their waking hours.

Researchers from the University of California tested the theory of time-restricted eating (TRF). The 392 mice that were tested were given different diets fed over different time frames. With plans on testing this on people, they fed the mice their normal diet, as well as a low-fat, high-fructose diet; a high-fat diet; and a high-fat, high-sugar diet. In all testing situations, the mice were given the same amount of calories. The difference was that they ate their food over 24 hours a day, 15 hours, 12 hours or nine hours. The study compared the weight of the mice on each diet and their time frame for eating.

Calories in all testing conditions were the same. With the high-fat, high-sugar diet, mice eating over nine hours gained 21 percent of their weight. If they were fed over 24 hours, they gained 42 percent of their weight. Mice fed the high-fat diet over nine hours had a 26 percent weight gain. If they were fed over 24 hours, they had a 65 percent weight gain. These results held even when the mice were allowed to “cheat” on the weekends.

Time-restricted eating led to a weight loss of up to 12 percent in mice who were already obese. Time-restricted eating did not impact weight gain for mice eating normal chow. Metabolic changes for the mice who ate on a time-restricted diet were reduced blood glucose and cholesterol levels. Beneficial effects were seen with an eating time of 12 hours or less.

Human studies are being planned but there are a few nuggets here to nibble on. If you are feeling frustrated about holiday weight gain or meeting a resolution to lose a few, try eating during the 12 active hours in the day. In simple terms, time dinner for 12 hours after breakfast and stop eating after dinner.

Sheah Rarback is a registered dietitian on the faculty of the University of Miami Leonard M. Miller School of Medicine. Follow her on Twitter @sheahrarback.