That's because the nutritionists seem to disregard the lifestyle side of th e equation. Nutrition is not a magic pill, especially if you're sedentary a nd/ or live in the typically toxic urban environment, the best and purest f ood in the world will not save you. Humans need physical toil to stay healt hy, without it you lose gene expression in middle age and beyond, and that' s what eventually kills you. An additional complication is the extent of va riability in metabolization of nutritional intake: what is a death sentence for one is the staff of life for another.