The nutritional geometry of aging

Abstract

There is currently considerable interest in whether dietary restriction prolongs longevity because of caloric restriction or whether more specific nutrient effects are involved. Here it is shown how the development of state-space geometric models in nutrition (the Geometric Framework) has provided a new approach to separating the effects of calories and nutrients. We introduce the models and illustrate their use in three recent studies on insects. Data from these organisms demonstrate that it is not calories per se that drives the relationship between diet and longevity, but rather the ratio of protein to non-protein energy ingested. It is argued that similar geometric analysis is required for mammalian model systems.