How to lose weight the easy way: go to sleep for longer

Sleeping for an extra 20 minutes each night could offer a pain-free way to lose weight, scientists suggested yesterday. Insufficient sleep is linked with changes in hormone levels that may stimulate appetite. A series of studies in recent months have shown that the less people sleep, the heavier they tend to be.

Sleeping for an extra 20 minutes each night could offer a pain-free way to lose weight, scientists suggested yesterday. Insufficient sleep is linked with changes in hormone levels that may stimulate appetite. A series of studies in recent months have shown that the less people sleep, the heavier they tend to be.

The research, from doctors at the Eastern Virginia Medical School in Norfolk, US, compared people of normal weight - a body mass index of less than 25 - with those who were overweight or obese.

Among 1,000 volunteers, they found those of normal weight slept on average 16 minutes a day more than those who were overweight or obese.

The difference between the groups reached 112 minutes or 1.86 hours over a week. That was after allowing for a difference between the sexes - men slept 27 minutes less a day on average than women.

Concern is growing that the obesity epidemic, which has hit developed countries in the past 20 years could be driven in part by stressful lifestyles that lead to sleep deprivation.

The researchers write in Archives in Internal Medicine: "Americans experience insufficient sleep and corpulent bodies. Our findings suggest major extensions of sleep time may not be needed, as an extra 20 minutes of sleep a night seems to be associated with a lower BMI."

The findings are counter-intuitive because individuals are likely to burn more calories, and hence might be expected to be slimmer, the longer they are awake. But previous research has shown hormone levels vary according to how long people sleep.

It was reported last month that people who slept for only five hours a night had higher levels of the hormone ghrelin, which stimulates appetite.