Researchers with the University of California have found that diets mimicking fasting offer health benefits in mice, at least when followed regularly on five-day cycles. The faux fasting diet helped counteract the health impact of the high-calorie and high-fat diet fed to the mice, which were split into three groups and studied for more than two years.
Fasting, once a common activity among the religious, has entered the mainstream as a diet and lifestyle trend for those seeking weight loss, improved insulin resistance, longer lifespans, and other purported benefits. Whereas religious dieting often involves abstaining from food and possibly water for multiple days, dieters and lifestyle hackers tend to participate in intermittent fasting.
Intermittent fasting typically involves avoiding all food and, usually, beverages that contain calories for a certain block of time every day; this could, for example, involve only eating one meal a day or limiting all of one’s meals to a six-hour period of time. We’ve seen some studies pop up that look into fast-like diets that essentially ‘trick’ the body into a fasting state without entirely eliminating food.
That faux fasting protocol is the subject of the new study, which refers to it as a fasting-mimicking diet (FMD) that involves eating a low amount of calories five days a week followed by two days of normal eating. One group of mice was fed a high-fat and high-calorie diet until they became overweight and developed health problems as a result. A second group was fed the same high-fat diet for four weeks but then put on the five-day fasting-mimicking low-calorie diet.
That cyclical dietary intervention, though mild in the grand scheme of things, was enough to trigger the return of normal body weight, cholesterol, and blood pressure levels in the second group of mice. That same group also had the same lifespan as the third group of mice, which were fed a normal, consistent, and healthy diet.
The study’s senior author Valter Longo explained:
The study indicates that it’s possible for mice to eat a relatively bad diet that is counterbalanced by five days of a fasting-mimicking diet. Our major discovery is that intervening with this diet made their hearts more resilient and better functioning than the mice who only ate a high-fat, high-calorie diet.