Intermittent fasting has quickly become one of the most popular types of diets in this country. How well do they work was the question addressed by University of Mississippi nutritionists. They found that one type of intermittent fasting, time-restricted eating, that is eating only within certain time periods each day, and paired with exercise can help healthy people lose fat and, importantly, not lose lean muscle. The fat loss for those combining exercise with eight hours a day of time-restricted eating for at least four weeks was greater than exercise alone. Authors of the article in the International Journal of Obesity say time-restricted eating is popular because it is all about time, not calorie counting or watching out for certain foods.