It has long been recognized that sleep patterns change with age. A common feature of aging is the advance of the timing of sleep to earlier hours, often earlier than desired. Polysomnographically-recorded sleep in older people shows an increased number of awakenings, a reduction of stages 3 and 4 (SWS) sleep, and a flattening of REM sleep distribution throughout the night. These age-related changes are found in even healthy individuals who are not taking medications and who are free from sleep disorders. In addition to these sleep disturbances, many older individuals curtail their sleep voluntarily, reporting similar rates of sleep restriction (sleeping less than 7 or less than 6 hours per night) as young adults. Whether voluntary or not, insufficient sleep has medical, safety and metabolic consequences. In fact, converging evidence in young adults suggests that sleep restriction per se may impair metabolism, and that reduced sleep duration is associated with weight gain, obesity, diabetes, cardiovascular disease, and mortality.