Design characteristics of worksite environmental interventions for obesity prevention.

OBJECTIVE: This paper describes the design characteristics of the National Heart, Lung, and Blood Institute (NHLBI)-funded studies that are testing innovative environmental interventions for weight control and obesity prevention at worksites. RESEARCH METHODS AND PROCEDURES: Seven separate studies that have a total of 114 worksites ( approximately 48,000 employees) across studies are being conducted. The worksite settings include hotels, hospitals, manufacturing facilities, businesses, schools, and bus garages located across the U.S. Each study uses its own conceptual model drawn from the literature and includes the socio-ecological model for health promotion, the epidemiological triad, and those integrating organizational and social contexts. The interventions, which are offered to all employees, include environmental- and individual-level approaches to improve physical activity and promote healthful eating practices. Environmental strategies include reducing portion sizes, modifying cafeteria recipes to lower their fat contents, and increasing the accessibility of fitness equipment at the workplace. Across all seven studies about 48% (N = 23,000) of the population is randomly selected for measurements. The primary outcome measure is change in BMI or body weight after two years of intervention. Secondary measures include waist circumference, objective, and self-report measures of physical activity, dietary intake, changes in vending machines and cafeteria food offerings, work productivity, healthcare use, and return on investment. DISCUSSION: The results of these studies could have important implications for the design and implementation of worksite overweight and obesity control programs.