A new mouse study shows that a longer time span between dinner and breakfast is associated with lower weight gain even on some high-fat diets.
Researchers analyzed two groups of mice on high-fat diets – first group had to eat its daily amount of calories on a strict 8-hour time window, while the second group had to eat the same amount of calories with no time restrictions. The mice that ate whenever they wanted to became obese and almost diabetic.
Researchers said that this proved that unhealthy eating habits such as late-night dining and snacking during day time might be associated with obesity and other modern diseases.
The new research was published Wednesday in “Cell Metabolism” journal by a group of researchers from Salk Institute for Biological Studies, California.
Very few people eat at very strict time intervals since work and sleep hours often make it impossible. Researchers said that our ancestors and even people closer to us in time were eating during a shorter time span than we are. Most of them had at most a three-meal per day habit (if any food was available) and didn’t serve any snack or late-night meal.
Many people say that weight gain and heart problems shouldn’t be a problem to them, since they eat only healthy food while they have snacks and eat late. However, the new study contradicts them – the time frame across which we eat is more important even than a low calorie diet.
The mice in the experiment were fed a diet that had about 60% of its calories from fats. Half of the mice were allowed to eat all three meals only within an 8-hour time frame, while the other half ate whenever they wanted to. The mice with a time-restricted diet quickly adapted and ate all their food within the 8 hours.
After 13 weeks, the results were astonishing – the mice that ate freely gained weight, high cholesterol, liver damage and prediabetes. The other mice were 28% slimmer, had no health problems and were in excellent shape. In humans, a 28 percent weight gain equals to an extra 56 pounds (25 kilo).
Researchers explained what happened. They said constant eating deprived mice bodies of an important chance of self-maintenance. When mice ate all day long, their bodies stored fat that added weight and put extra stress on liver. Liver had to constantly produce glucose that elevated blood sugar levels and thus led to type 2 diabetes. On the other hand, mice that stopped eating for 8 hours allowed their liver to rest and use the glucose to repair cellular damage. Liver had also time to release enzymes that fight cholesterol and turn it into acids. So, mice that were on a time restricted diet were healthier, thinner and more energetic.
Researchers caution that this doesn’t mean that we should adjust our eating schedule and start eating as many fats as we want, because a healthy weight is not more important than a nutritious diet.