BACKGROUND: Obesity and overweight are significant public health problems in the US, prompting policy makers and researchers to call for action against the epdiemic. Obesity/overweight and associated health conditions affect all age groups and both genders, yet disproportionately affect racial/ethnic minorities. Health consequences of obesity and overweight include high blood pressure, high cholesterol, hyperinsulinemia and type 2 diabetes, heart disease and stroke, gallbladder disease, arthritis, sleep disturbances, breathing problems, and certain types of cancer. Hospitals are important worksite environments that employ large numbers of people in diverse job categories from diverse educational and socioeconomic backgrousnds.

DESIGN NARRATIVE: A randomized controlled trial to promote weight loss among those who are overweight and obese, and prevent weight gain among those of normal weight through an environmental intervention targeted at all employees at 6 hospitals in central Massachusetts. The sites will be matched on size, and within each matched pair, randomly assigned to either the intervention or control condition. The intervention promotes active living, in which physical activity is incorporated into daily routine, and prudent diet, characterized by higher intakes of fruits and vegetables, fish, poultry, legumes and whole grains, lower intakes of high fat foods and refined grains and reduction of total caloric intake through reduced portion sizes.