title: Meta-analyses of workplace physical activity and dietary behaviour interventions on weight outcomes.
abstract: This meta-analytic review critically examines the effectiveness of workplace interventions targeting physical activity, dietary behaviour or both on weight outcomes. Data could be extracted from 22 studies published between 1980 and November 2009 for meta-analyses. The GRADE approach was used to determine the level of evidence for each pooled outcome measure. Results show moderate quality of evidence that workplace physical activity and dietary behaviour interventions significantly reduce body weight (nine studies; mean difference [MD]-1.19 kg [95% CI -1.64 to -0.74]), body mass index (BMI) (11 studies; MD -0.34 kg m⁻² [95% CI -0.46 to -0.22]) and body fat percentage calculated from sum of skin-folds (three studies; MD -1.12% [95% CI -1.86 to -0.38]). There is low quality of evidence that workplace physical activity interventions significantly reduce body weight and BMI. Effects on percentage body fat calculated from bioelectrical impedance or hydrostatic weighing, waist circumference, sum of skin-folds and waist-hip ratio could not be investigated properly because of a lack of studies. Subgroup analyses showed a greater reduction in body weight of physical activity and diet interventions containing an environmental component. As the clinical relevance of the pooled effects may be substantial on a population level, we recommend workplace physical activity and dietary behaviour interventions, including an environment component, in order to prevent weight gain.
authors.affiliation: Department of Public and Occupational Health and the EMGO Institute for Health and Care Research, VU University Medical Center, Body@Work, Research Center Physical Activity, Work and Health, TNO-VUmc, Amsterdam, The Netherlands.
authors.forename: L M
authors.initials: LM
authors.lastname: Verweij
authors.forename: J
authors.initials: J
authors.lastname: Coffeng
authors.forename: W
authors.initials: W
authors.lastname: van Mechelen
authors.forename: K I
authors.initials: KI
authors.lastname: Proper
mesh_terms: D000273:Adipose Tissue; D001521:Behavior Therapy; D001823:Body Composition; D001835:Body Weight; D005247:Feeding Behavior; D006801:Humans; D009043:Motor Activity; D009765:Obesity / Q000517:prevention & control; D016032:Randomized Controlled Trials as Topic; D055105:Waist Circumference; D049629:Waist-Hip Ratio; D015430:Weight Gain; D017132:Workplace