How Much Sleep Is Optimal for Staying Thin?

How much sleep is optimal for staying skinny? 7-9 hours is best. Less than 7 hours increases the risk of obesity ~ 30% and adds an extra 5 pounds on average.

According to Jean-Philippe Chaput, MSc, from Laval University in Quebec City, Quebec, Canada, and colleagues, "Current treatments for obesity have been largely unsuccessful in maintaining long-term weight loss, suggesting the need for new insight into the mechanisms that result in altered metabolism and behavior and may lead to obesity."

The increase in body weight in the US population has been paralleled by a reduction in sleep times. For the past 4 decades, daily sleep duration has decreased by 1.5 to 2 hours, and the proportion of young adults sleeping less than 7 hours per night has more than doubled, from 15.6% in 1960 to 37.1% from 2001 to 2002.

Studies in adults and children have repeatedly shown that reduced sleep is associated with increased weight.

To determine the relationship between sleep duration and weight, researchers followed up 276 adults aged 21 to 64 years who were enrolled in the Quebec Family Study, a 6-year longitudinal study in a community setting. The investigators compared weight gain relative to sleep duration: short (5-6 hours), average (7-8 hours), and long (9-10 hours).

Compared with average-duration sleepers, short-duration sleepers gained 4.4 pounds more in a 6-year period. At 6 years, short-duration and long-duration sleepers were 35% and 25% more likely to experience a 12 pound weight gain, respectively, compared to those who slept 7-8 hours a night.

Compared with average-duration sleepers, short-duration sleepers had a 27% increased risk for the development of obesity, and long-duration sleepers had a 21% increase in risk. Adjustment for caloric intake and physical activity did not affect these connections.

References

Sleep. 2008;31:517-523.

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