Efficacy of a workplace-based weight loss program for overweight male shift workers: the Workplace POWER (Preventing Obesity Without Eating like a Rabbit) randomized controlled trial

Prev Med. 2011 May;52(5):317-25. doi: 10.1016/j.ypmed.2011.01.031. Epub 2011 Feb 20.


Objective: To evaluate the feasibility and efficacy of a workplace-based weight loss program (Workplace POWER-WP) for male shift workers.

Method: A prospective, two-armed randomized controlled trial of 110 overweight/obese (BMI 25-40) (mean [SD] age = 44.4 [8.6] years; BMI = 30.5 [3.6]) male employees at Tomago Aluminium aged 18-65. In October (2009) men were randomized to either (i) WP program (n=65) or (ii) a 14-week wait-list control group (n=45). The 3-month program involved one information session, program booklets, group-based financial incentives and an online component. Men were assessed at baseline and at 14-week follow-up for weight (primary outcome), waist circumference, BMI, blood pressure, resting heart rate, self-reported physical activity and dietary variables, and physical activity and dietary cognitions.

Results: Intention-to-treat analysis using linear mixed models revealed significant between group differences for weight loss after 14 weeks (P < .001, Cohen's d = 0.34). Significant intervention effects were also found for waist circumference (P < .001, d = 0.63), BMI (P < .001, d = 0.41), systolic blood pressure (P = .02, d = 0.48), resting heart rate (P < .001, d = 0.81), physical activity (P = .03, d = 0.77), sweetened beverages (P < .02, d = 0.5-0.6) and physical activity-related cognitions (P < .02, d=0.6).

Conclusion: The WP program was feasible and efficacious and resulted in significant weight loss and improved health-related outcomes and behaviours in overweight male shift workers.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Health Promotion*
  • Humans
  • Male
  • Middle Aged
  • New South Wales
  • Obesity / prevention & control*
  • Occupational Health
  • Prospective Studies
  • Treatment Outcome
  • Weight Loss*
  • Work Schedule Tolerance
  • Workplace*
  • Young Adult