Weight loss workbook: can you sleep your way thin?

Shape, March, 2005 by Kathleen Doheny

Don't blame only your sweet tooth for excess pounds--lack of rest might contribute too. Researchers followed nearly 500 men and women for 13 years and found that people age 35 and younger who slept less than six hours a night were more likely to have a higher body mass index (BMI). Exactly why sleep and weight are linked in younger people isn't known for sure, but "as sleep declines, hormones such as leptin decline," says lead researcher Gregor Hasler, M.D., a postdoctoral fellow at the National Institute of Mental Health in Bethesda, Md.

"When leptin goes down, appetite increases." Aim for between seven and nine hours of sleep a night.--K.D.