Researchers first discovered the connection between lean diets and extended life spans in a 1935 study of calorie - restricted rats. (sciencemag.org)
Whilst lean diets are associated with normal levels of leptin, obesity causes levels to rise and remain consistently higher than normal. (sciencedaily.com)
Leaner diets also reduced muscle and brain gray matter deterioration, two conditions associated with aging. (sciencemag.org)