Second-year results of an obesity prevention program at The Dow Chemical Company

Objective: To evaluate the impact of adding worksite environmental changes to reduce obesity-related health risks to standard individual-focused obesity management interventions at a large multi-site employer.

Methods: The NHLBI-funded LightenUP program introduced environmental interventions designed to encourage physical activity and healthy eating at The Dow Chemical Company. In a quasi-experimental study, five sites received intense interventions (individual + environmental + management commitment programs), four sites received moderate interventions (individual + environmental programs), and three control sites received standard individual programs. Participants (n=4,776) completed a Health Risk Assessment and biometric screening at baseline and at two-year follow-up. Longitudinal change across intervention and control sites was assessed using a difference-in-difference analysis. Baseline intervention and control site differences were equalized using propensity score weights.

Results: At follow-up, average weight loss at the intervention sites was significantly greater than control sites (1.58 pounds difference; p = 0.005), as were reductions in mean blood pressure (difference is 7.05 mm Hg for Systolic and 1.65 mm Hg for Diastolic, p=0.003 and p < 0.0001) and cholesterol levels (difference is 3.64, p = 0.02). Intervention sites achieved significantly greater improvement in diet (9.0% change vs. 2.6% change, p=0.0005) and exercise (3.1% change vs. 0.1% change, p=0.015). However, a greater increase in the high-risk category for overweight/obesity at intervention sites (baseline: 70.77%; follow-up: 72.94%) than in the control sites (baseline: 74.82%; follow-up:72.56%) was observed.

Conclusions: Adding environmental interventions to individual-level programs improved biometric and behavioral risk factors. Reduced risk of overweight/obesity may necessitate a longer intervention period, however.