Our timing of energy restriction prior to, but not after, chemotherapy administration avoids any theoretical reductions in cytotoxic effects on cancer cells alongside reductions in mitogens like insulin and IGF-1 and the available pool of proliferating cells as reported in preclinical studies with doxorubicin, fluorouracil, cyclophosphamide and docetaxel [51, 52]. This evidence concerns the gene IGF1 and cancer.