One of the purposes of this 2‐year multicenter randomized controlled trial (CALERIE) was to evaluate the effects of a 25% reduction in energy intake in a large number of nonobese young and middle‐aged men and women on the IGF‐1 axis, and other growth and hormonal factors modulated by CR, which have been implicated in the biology of aging and in the pathophysiology of cancer, such as PDGF‐AB, TGF‐β‐1, and cortisol. Here, IGF1 is linked to cancer.