We all know that healthy eating, reduced calorie intake, and regular exercise are paramount to losing excess pounds and maintaining a healthy weight. But, these practices are only successful in a small fraction of the obese and overweight population.
Researchers have found a new strategy for losing weight. According to a study by the Salk Institute in La Jolla, California, restricting your eating to a specific number of hours in the day may help you shed the pounds, even while eating a high-fat diet.
The researchers studied about 400 mice for 12 to 26 weeks, dividing them into groups and implementing time-restricted feeding (TRF) in some of the groups. In the TRF groups, they limited the amount of time these mice could eat to nine hours, 12 hours, or 15 hours each day. Mice not in the TRF groups were allowed to eat at all times of the day.
Some mice in the time-restricted and free-feeding groups were given a high-fat diet. In those eating this diet, the mice that were able to eat as often as desired were given the same amount of calories as the mice in the TRF group.
Based on these results, the authors found that the health “benefits were proportional to the fasting duration.” Even with this same high-fat caloric intake, the TRF mice didn’t gain nearly as much weight as those mice that could eat whenever they pleased throughout night and day.
After 100 days, the free-feeding group of mice showed illness symptoms. They had developed high cholesterol, high blood glucose, impaired motor control, and liver damage, including an unhealthy amount of fat in the liver.
The mice that were restricted to eating nine hours and 12 hours a day had none of the ill health symptoms that were recorded in the free-feeding mice. Plus, they didn’t gain weight when the time restriction was temporarily lifted during the weekends, which reflects the typical human lifestyle.
Already-obese mice lost weight in time-restricted feeding—up to 12 percent weight loss. In contrast, the mice that transferred from time-restricted eating to non-restricted eating periods experienced rapid weight gain in a matter of weeks.
TRF had a direct effect on metabolic diseases like type 2 diabetes: “TRF stabilized and reversed the progression of metabolic diseases in mice with preexisting obesity and type 2 diabetes.”
So what is it about fasting that helps with weight loss?
Even though this research was performed on mice, the researchers believe the findings are significant for humans since our metabolisms are very similar to the little critters. They argue that our constant eating pattern not only makes us gain weight, but also “may deprive our body of an important chance to maintain itself.”
While we eat, our bodies store fat, which adds weight and subjects the liver to stress. Our liver produces glucose as we eat, which increases blood sugar levels and can create insulin insensitivity, both indicators of diabetes.
When we don’t eat for several hours, the liver stops secreting glucose into the bloodstream, and instead uses the glucose to repair cell damage. The liver also releases enzymes that break down our cholesterol into acid. These acids then dissolve brown fat, and this brown fat in turn converts calories into heat. Therefore, during our fasting period, the liver is helping burn off fat and repair our bodies.
How to apply this research to your own life
Although there hasn’t been a human trial of TRF vs. free-feeding, incorporating these better eating patterns can only benefit us. So what can we learn from this study and how do we implement it into our daily lives?
If you’d like to see how time-restricted feeding works for you, try to eat for only 12 hours a day, perhaps from 7:00 a.m. to 7:00 p.m. or 8:00 a.m. to 8:00 p.m. Rid yourself of late-night snacking and right-before-bed dinners and see how these changes affect your weight over a period of a month.