The Los Angeles Times looks at the science of intermittent fasting, one approach to calorie restriction: "In normal health subjects, moderate fasting - maybe one day a week or cutting back on calories a couple of days a week - will have health benefits for most anybody ... We're not good at responding to too many calories, but we're very good at responding to fasting. Fasting, in itself, is not an unhealthy process ... During fasting, almost every system in the body is 'turned down,' ... The body changes how it uses fuel. Certain hormone levels fall. Growth stops. Reproduction becomes impossible. ... By the end of three weeks of fasting you are a completely different metabolic creature. It affects many, many processes - but in a somewhat predictable way that takes you toward disease prevention. ... intermittent fasting appears to offer the same advantages as long-term calorie restriction - defined as eating at regular times but consuming 25% to 30% fewer calories than what is recommended for that person based on age, size and gender."