If you want to slow aging, you might want to eat less. Researchers in the United States say eating less can slow the aging process of cells in the body. This finding is good news if you are a mouse. The researchers studied mice, not people. John Price is a biochemistry professor at Brigham Young University in the U.S. state of Utah. He and other researchers studied two groups of mice. One group was able to eat as much as it wanted. The researchers restricted what the other animals in the other group ate. Their diet had 35 percent fewer calories than the first group of mice. Price says the mice with the diet restrictions were more energetic and suffered fewer diseases. They were not just living longer, they seemed to stay younger for a longer period of time. Price says that when you restrict calories, there is a direct increase in lifespan the average age of the animal. He and his team found that calorie restriction caused real biochemical changes that slowed down the rate of aging.