FuturePundit looks at one of a number of studies showing calorie restriction to reduce the risk of cancer: "Previous studies have shown that intermittent calorie restriction provided greater protection from mammary tumor development than did the same overall degree of restriction, which was implemented in a chronic fashion. The researchers compared changes of a growth factor (IGF-1) in relationship to these two calorie restriction methods - chronic and intermittent - and tumor development beginning in 10-week old female mice at risk to develop mammary tumors. Their hope was to explain why intermittent restriction is more effective. The overall degree of restriction was 25 percent reduction compared to control mice. Mammary tumor incidence was 71 percent in the control mice who ate the amount of food they wanted, 35 percent among those who were chronically restricted and only nine percent in those who intermittently restricted calories." Which is further evidence for those who suspect that intermittent fasting operates through different biochemical mechanisms to calorie restriction, despite a similar outcome in terms of extended health and longevity.