The secret to keeping slim may be not so much what you eat, but when you eat. Researchers at the Salk Institute found that limiting eating to an 8- to 12-hour time frame may fend off high cholesterol, diabetes and obesity.
 

This restricted eating pattern, researchers say, mimics the way Americans ate 100 hundred years ago before artificial light became widespread, and we stayed up late watching television and using computers. Later bedtimes, they contend, bring a tendency to eat late into the evening hours.
 

In 2012, a study at Salk showed that mice who ate a high-fat diet, but were allowed access to food for only eight hours, were slimmer and healthier than mice who ate the same number of calories but were allowed access to the same food for the entire day. The study showed that time restriction had a greater impact than previously thought, and can reverse obesity and diabetes in animals.
 

The researchers found that predictable eating times help synchronize the function of hundreds of genes.  
 

"These days, most of the advice is, 'You have to change nutrition, you have to eat a healthy diet,'" said researcher Satchidananda Panda. "But many people don’t have access to healthy diets. So the question is, without access to a healthy diet, can they still practice time-restricted feeding and reap some benefit?"
 

Panda wanted to know just how lenient time-restriction would be. He studied almost 400 mice, ranging from normal to obese, giving them different diets and lengths of time to eat. He found that time-restricted feeding was beneficial regardless of how much the mice weighed or the type of diet they ate.
 

The mice that ate high-fat diets, diets high in fat and sugar, or diets just high in sugar and were given time restrictions of 9 to 12 hours, gained less weight than mice who ate the same amount of calories but were allowed unrestricted eating hours.
 

Some mice were given a break over the weekend and were allowed unrestricted access to high-fat diets. These mice also gained less than the mice given access to a high-fat diet without restrictions.
 

"The fact that it worked no matter what the diet, and the fact that it worked over the weekend and weekdays, was a very nice surprise," said Amandine Chaix, a postdoctoral researcher in Panda's lab.
 

In addition, when mice that were obese after freely eating an unrestricted high-fat diet were limited to eating during a nine-hour time frame, they dropped about five percent of their body weight in a few days, although they were eating the same number of calories.