"Dietary caloric restriction (CR) is the only intervention conclusively and reproducibly shown to slow aging and maintain health and vitality in mammals. "
http://onlinelibrary.wiley.com/doi/10.1111/j.1749-6632.2001.tb05660.x/abstract
"Preliminary information obtained using this approach provides evidence that CR provides a powerful protective effect against secondary aging in humans. "
"These include a very low level of inflammation as evidenced by low circulating levels of c-reactive protein and TNFα, serum triiodothyronine levels at the low end of the normal range, and a more elastic “younger” left ventricle (LV), as evaluated by echo-doppler measures of LV stiffness."
http://www.sciencedirect.com/science/article/pii/S0531556507000630
"Restriction of caloric intake lowers steady-state levels of oxidative stress and damage, retards age-associated changes, and extends the maximum life-span in mammals."
http://m.sciencemag.org/content/273/5271/59.short
"The report findings of a 20-year longitudinal adult-onset CR study in rhesus monkeys aimed at filling this critical gap in aging research. In a population of rhesus macaques maintained at the Wisconsin National Primate Research Center, moderate CR lowered the incidence of aging-related deaths. At the time point reported, 50% of control fed animals survived as compared with 80% of the CR animals. Furthermore, CR delayed the onset of age-associated pathologies. Specifically, CR reduced the incidence of diabetes, cancer, cardiovascular disease, and brain atrophy. These data demonstrate that CR slows aging in a primate species."
http://m.sciencemag.org/content/325/5937/201.short
Although there is still debate on the topic as what is actually leading to delayed ageing: calorie restriction vs weight?
And also whether the studies contacted showed delayed ageing due to different diets.
"Meanwhile, there is a dearth of evidence that caloric restriction slows ageing in humans. Observational studies have found that people of average weight tend to live longest "
http://www.nature.com/news/calorie-restriction-falters-in-the-long-run-1.11297#/
http://www.ncbi.nlm.nih.gov/pubmed/21121834?dopt=Abstract&holding=npg
"Calorie restriction without malnutrition has been shown to work in a variety of species, among them yeast, fish, rodents and dogs to decelerate the biological aging process, resulting in longer maintenance of youthful health and an increase in both median and maximum lifespan.[1] The life-extending effect of calorie restriction however is not shown to be universal.[2]"
https://en.m.wikipedia.org/wiki/Calorie_restriction
http://healthland.time.com/2012/08/29/want-to-live-longer-dont-try-caloric-restriction/