Eating less may help people live longer, reports CNN.com. Scientists at Louisiana State University tested the effects of calorie restriction on 53 healthy men and women between 21 and 50 years old. For two years, one-third of the volunteers ate their normal diet, while the rest cut their caloric intake by 15 percent. Unsurprisingly, those who consumed fewer calories lost weight—about 20 pounds on average. But they also saw another benefit: Their metabolic rate, which governs the amount of energy the body requires to sustain normal daily functions, slowed by about 10 percent during sleep. “It’s important because every time we generate energy in the body, we generate byproducts,” explains lead author Leanne Redman. These so-called free radicals accumulate and cause damage to cells and organs; this damage has been linked to diabetes, cancer, Alzheimer’s, and other age-related diseases. Previous studies have shown that reducing calories can extend life in rodents and other animals, but there has been little research to see if the same is true in humans. Redman now wants to examine the effects of reducing calorie intake over a much longer period.