In contrast to the traditional weight-centered approach, the Health At Every Size (HAES) or nondieting approach is health centered, with no focus on losing a predetermined amount of weight or fat. A key HAES principle of advocating healthy changes in food selection rather than adherence to prescriptive diets that involve calorie counting was adopted by Wellness in the Rockies (WIN the Rockies), a community-based research, intervention, and outreach project that promoted healthy lifestyles related to food, physical activity, and body image at the individual and community levels in Wyoming, Montana, and Idaho. The results from the project's cross-sectional surveys indicated that increased frequency of eating food while doing another activity, of drinking sweetened beverages such as soft drinks, and of consuming foods from fast-food restaurants were significant predictors of a high body mass index (BMI). In terms of energy expenditure, other predictors of high BMI from the WIN the Rockies cross-sectional surveys were lower frequency of participation in physical activity and the perception of not getting as much exercise as needed. The overall data provide support for the view that small diet- and physical activity-related lifestyle changes can cumulatively make a significant contribution to maintenance of healthy body weights. Although the community intervention emphasis of WIN the Rockies did not allow a specific assessment of the efficacy of HAES for individual participants in the project, this approach appears to hold great potential for promoting healthful lifestyle changes that improve quality of life.