Dietary restriction and aging: a unifying perspective.

Dietary restriction (DR) and mutations in nutrient signaling pathways can extend healthy life span in diverse organisms. Studying the interaction between these interventions should reveal mechanisms of aging, but has yielded some apparently contradictory results. A multidimensional representation of nutrition, called the geometric framework, can better describe the responses of life span and other traits, including metabolism, and can reconcile these apparent contradictions. We provide examples showing that it is more informative to analyze DR in terms of dietary balance and that dietary optimization for life span is critical for studies examining the biology of aging and other traits.