Additionally, school feeding programs are increasingly being viewed as a potential safety net and as a social support measure that helps keep children in school.
The first REM sleep period usually occurs about 70 to 90 minutes after we fall asleep. A complete sleep cycle takes 90 to 110 minutes on average. The first sleep cycles each night contain relatively short REM periods and long periods of deep sleep.
Human sleep occurs in periods of approximately 90 minutes, which include increasing proportions of paradoxical (REM) sleep as they repeat. This rhythm is called the ultradian sleep cycle. Sleep proceeds in cycles of NREM and REM, normally in that order and usually four or five of them per night. The American Academy of Sleep Medicine (AASM) divides NREM into three stages: N1, N2, and N3, the last of which is also called delta sleep or slow-wave sleep.