The idea that restricting calories can lead to a longer life has been intriguing scientists for some time. Studies involving small animals, such as mice, have led some researchers to conclude that diets low in calories but high in nutrient density may indeed extend longevity in all species. However, a new study warns that the benefits of calorie restriction may not translate to significantly longer lives in humans.
Writing in the August 2005 issue of Aging Research Reviews, the researchers described the mathematical model they used to assess the effects of calorie intake on life span. “Applying this general model to the special case of human longevity and diet indicates that the benefits of caloric restriction in humans would be quantitatively small,” said the researchers. They concluded that a lifetime of low-calorie eating would extend longevity in humans by only about 7%, whereas animals’ life spans—which are much shorter—are substantially increased by the effects of starvation.