! A new review on the positive effects on lifespan and health of fasting and calorie restriction.

Nutrient composition and caloric intake have traditionally been used to devise optimized diets for various phases of life. Adjustment of meal size and frequency have emerged as powerful tools to ameliorate and postpone the onset of disease and delay aging, whereas periods of fasting, with or without reduced energy intake, can have profound health benefits. The underlying physiological processes involve periodic shifts of metabolic fuel sources, promotion of repair mechanisms, and the optimization of energy utilization for cellular and organismal health. Future research endeavors should be directed to the integration of a balanced nutritious diet with controlled meal size and patterns and periods of fasting to develop better strategies to prevent, postpone, and treat the socioeconomical burden of chronic diseases associated with aging.

The worldwide increase in life expectancy has not been paralleled by an equivalent increase in healthy aging. Developed and developing countries are facing social and economic challenges caused by disproportional increases in their elderly populations and the accompanying burden of chronic diseases. Geriatricians and gerontologists have contributed greatly to our understanding of the consequences and processes that underlie aging from clinical, social, mental, physical, and biological perspectives. The primary goal of aging research is to improve the health of older persons and to design and test interventions that may prevent or delay age-related diseases. Besides socioeconomic status, energy, environmental quality, and genetics are the most powerful determinants of health and longevity. Although environmental quality and genetics are not under our direct control, energy intake is.