title: Sleeping habits predict the magnitude of fat loss in adults exposed to moderate caloric restriction.
abstract: OBJECTIVE
  To verify whether sleep quantity and quality at baseline predict the magnitude of fat loss in adults subjected to moderate caloric restriction.
  
  
  METHODS
  A total of 123 overweight and obese men and women (age, 41.1 ± 6.0 years; BMI, 33.2 ± 3.6 kg/m2 (mean ± SD)) underwent a weight loss intervention consisting of a targeted 600-700 kcal/day decrease in energy intake supervised by a dietician. The length of the intervention varied between 15 and 24 weeks. Body fat mass (dual-energy X-ray absorptiometry), sleep quality (total Pittsburgh sleep quality index score) and sleep duration (h/night, self-reported from the Pittsburgh sleep quality index) were assessed at both baseline and at the end of the weight loss program.
  
  
  RESULTS
  The mean weight loss over the dietary intervention was 4.5 ± 3.9 kg, 76% of which came from fat stores. Using a multiple linear regression analysis, we observed a significant positive relationship between sleep duration and the loss of body fat, both in absolute (adjusted β = 0.72 kg/h; p < 0.05) as well as in relative terms (adjusted β = 0.77%/h; p < 0.01), after adjusting for age, sex, baseline BMI, length of the intervention, and change in total energy intake. Furthermore, we observed that a better sleep quality at baseline was associated with greater fat mass loss.
  
  
  CONCLUSIONS
  This study provides evidence that sleeping habits can influence the success of a weight loss intervention and should be taken into consideration when one decides to start a diet.
authors.affiliation: Healthy Active Living and Obesity Research Group, Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada. jpchaput@cheo.on.ca
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Chaput
authors.forename: Angelo
authors.initials: A
authors.lastname: Tremblay
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D031204:Caloric Restriction; D004038:Diet, Reducing; D005260:Female; D006184:Habits; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy; D057566:Self Report; D012890:Sleep; D015431:Weight Loss