BACKGROUND: More than half of all Americans are overweight or obese, and the prevalence of these risk factors has increased dramatically in the past decade. Obesity is a risk factor for several chronic disease conditions including type-2 diabetes and cardiovascular disease. The national medical cost burden attributable to overweight and obesity is estimated to be between $60 and $93 billion. Business leaders are becoming increasingly aware of the human and economic burden that poor health imposes on their workers. Many employers have invested in health promotion and disease prevention programs aimed at reducing the prevalence of obesity in the workplace through encouragement of physical activity, healthy diet, and improved management of health risk factors. Employers continue to seek innovative and evidence-based interventions that can be imported into the workplace to address a growing public health epidemic that also adversely affects worker productivity.

DESIGN NARRATIVE: The primary objective of the study is to evaluate the marginal effects of introducing two levels of environmental interventions directed at reducing overweight and obesity in the workplace, on top of existing individualized interventions, on five sets of outcomes: a. body mass index and other weight-related biometric measures; b) behavioral health risk factors; c) weight-related health conditions; d) health care utilization and medical expenditures; and e. employee productivity measured in terms of reduced absenteeism and on-the job presenteeism. The design also includes an assessment of costs and benefits of the two treatments, considering the medical, absenteeism and productivity benefits derived from such interventions, an assessment of the impact of the interventions on the worksite climate. Twelve Dow chemical companies will participate in the study. They will be randomly assigned to a moderate environmental treatment, an intensive environmental treatment, or control (individualized treatment only). The moderate interventions will include inexpensive environmental changes (e.g., prompts and reminders), while the high intensity intervention will involve engagement of senior managers in development of a worksite culture that is broadly supportive of improved weight and health management by employees. Annual health screening and biometrics data along with administrative medical claims, absence records, and productivity survey data will be analyzed to determine program impacts. Non-experimental statistical methods will be used to control for baseline differences that remain across sites after randomization. The study will also produce extensive information about how employers can successfully implement environmental treatments at worksites.