It looks plausible that some portion of the health and longevity benefits of calorie restriction stem from a reduction in the intake of dietary advanced glycation end products (AGEs). AGEs are created in the body as a metabolic side-effect, but also found in your food: "Increased oxidative stress (OS) underlies many chronic diseases prevalent in aging. Data in humans confirm the hypothesis that [AGEs] and other oxidants derived from the diet may be major contributors to increased OS in normal adults as well as those with diabetes mellitus or kidney failure. Mice fed a diet with a lowered (approximately 50%) content of AGEs or a typical calorie-restricted (CR) diet, accumulated a smaller amount of AGEs [and] did not have increased oxidant stress or cardiac or kidney fibrosis with aging. However, the findings in mice fed a CR diet with an increased content of AGEs resembled those in mice fed a nonrestricted diet that had the usual higher content of AGEs. Thus, there was an inverse correlation between the dietary AGE content, [oxidative stress], organ damage, and life span."