Sleep more to slim down, scientists say

An extra hour of sleep at night may help stabilize weight. The relation to lack of sleep and weight gain is often under-estimated. Two key hormones produced at night help regulate appetite. Grehlin makes people hungry, slows metabolism and decreases the body's ability to burn body fat, and leptin, a protein hormone produced by fatty tissue, regulates fat storage. Less sleep (two four-hour nights) has been shown to cause an 18 percent loss of appetite-cutting leptin and a 28 percent increase of appetite-causing grehlin. Such hormonal changes make people hungry for foods heavy in fats and sugars such as chips, biscuits, cakes and peanuts. The sleep loss caused a 23 to 24 percent increase in hunger, translating into an extra 350 to 500 calories a day.

A journal Obesity study released in February showed children lacking shut-eye faced a greater risk of becoming obese than kids who got a good night's sleep. Each extra hour of sleep cuts a child's risk of becoming overweight or obese by nine percent, according to an analysis of epidemiological studies by researchers from Johns Hopkins Bloomberg School of Public Health. By contrast, children who got the least sleep had a 92 percent higher chance of being overweight or obese than children who slept enough. Some research recommends that children under five years old sleep 11 hours or more a day, while children age five to 10 should get 10 or more hours of sleep, and children older than 10 should sleep at least nine hours.