Eating less often achieves a dramatic effect. An experiment in the United States showed that reducing the food intake of mice by 30% per day could extend their lives by as much as 30%. Even more incredibly, a thin person's heart may be 10 to 15 years younger than that of an obese person. Other related data shows that people who restrict calorie intake see significant improvements in their insulin levels compared to normal people, and there are also fewer signs of DNA damage. Scientists believe that controlling food intake can reduce the damage caused by excessively high blood sugar to tissues, lower the incidence of inflammation, and cut down on free radicals (the main culprit of aging).