Sleeping Beauty's BMI

A link between sleep deprivation and obesity

(RxWiki News) Everyone has heard a southern belle exclaim, “I NEED MY BEAUTY SLEEP”.

Well, apparently, she wasn’t just whistlin’ Dixie.

Emmanuel Mignot, MD, PhD and his Stanford colleagues studied levels of hormones known to regulate appetite and energy expenditures, by taking blood samples immediately after the participants woke from their sleep.

When studying the sleep duration, Body Mass Index (BMI ) and pre-breakfast hormone levels of 1,024 participants, they found that people who sleep less than 8 hours, have a BMI which is inversely proportional to their sleep duration.

In other words, the heavier they were, the less they slept.

"If you are trying to lose weight, get a good night’s sleep."

Short sleep was also associated with low leptin levels and high ghrelin levels. Ghrelin is a hormone which is believed to stimulate food intake.

Leptin is a hormone responsible for fat metabolism. This hormonal difference probably increases a sleepy person’s appetite, which could be responsible for the increased BMI.

Mignot and his colleagues referred to the Wisconsin Sleep Cohort Study. 

This study began in 1989 and conducts mail surveys every five years on sleep, health habits, health, and demographics.  Those surveyed are age 30-60. 

From those surveyed, the researchers selected some of the respondents to participate in a sleep in the laboratory study.  Some participants also kept a diary of the sleeping pattern for six days. 

This study already linked sleep apnea and hypertension with menopause and sleep-disordered breathing. 

Mignot's team was able to build on that original finding to find BMI has a directly inverse proportion to sleep duration.

In their next study, Mignot and colleagues plan to test forcing people who are not sleeping at least 8 hours a day and measure the effects on body mass.

Good sleep along with healthy eating habits, and regular exercise probably have important roles in fighting obesity.

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Review Date: 
March 26, 2011