title: Impact of sleep, screen time, depression and stress on weight change in the intensive weight loss phase of the LIFE study.
abstract: BACKGROUND
  The LIFE study is a two-phase randomized clinical trial comparing two approaches to maintaining weight loss following guided weight loss. Phase I provided a nonrandomized intensive 6-month behavioral weight loss intervention to 472 obese (body mass index 30-50) adult participants. Phase II is the randomized weight loss maintenance portion of the study. This paper focuses on Phase I measures of sleep, screen time, depression and stress.
  
  
  METHODS
  The Phase I intervention consisted of 22 group sessions led over 26 weeks by behavioral counselors. Recommendations included reducing dietary intake by 500 calories per day, adopting the Dietary Approaches to Stop Hypertension (DASH) dietary pattern and increasing physical exercise to at least 180 min per week. Measures reported here are sleep time, insomnia, screen time, depression and stress at entry and post-weight loss intervention follow-up.
  
  
  RESULTS
  The mean weight loss for all participants over the intensive Phase I weight loss intervention was 6.3 kg (s.d. 7.1). Sixty percent (N=285) of participants lost at least 4.5 kg (10 lbs) and were randomized into Phase II. Participants (N=472) attended a mean of 73.1% (s.d. 26.7) of sessions, completed 5.1 (s.d. 1.9) daily food records/week, and reported 195.1 min (s.d. 123.1) of exercise per week. Using logistic regression, sleep time (quadratic trend, P=0.030) and lower stress (P=0.024) at entry predicted success in the weight loss program, and lower stress predicted greater weight loss during Phase I (P=0.021). In addition, weight loss was significantly correlated with declines in stress (P=0.048) and depression (P=0.035).
  
  
  CONCLUSIONS
  Results suggest that clinicians and investigators might consider targeting sleep, depression and stress as part of a behavioral weight loss intervention.
authors: Kaiser Permanente Center for Health Research, Portland, OR, USA. Charles.Elder@kpchr.org
authors: C R
authors: CR
authors: Elder
authors: C M
authors: CM
authors: Gullion
authors: K L
authors: KL
authors: Funk
authors: L L
authors: LL
authors: Debar
authors: N M
authors: NM
authors: Lindberg
authors: V J
authors: VJ
authors: Stevens
mesh_terms: D001521:Behavior Therapy / Q000379:methods*; D015992:Body Mass Index; D003201:Computers; D003863:Depression / Q000453:epidemiology / Q000523:psychology / Q000628:therapy*; D004038:Diet, Reducing; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008019:Life Style; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology / Q000523:psychology* / Q000628:therapy*; D018579:Patient Selection; D012890:Sleep; D013315:Stress, Psychological / Q000150:complications*; D013690:Television; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D015431:Weight Loss; D061217:Weight Reduction Programs