Specific Aim: Test a multi-level worksite weight loss intervention to help workers attain and maintain healthy weight. Investigators propose a new group-level participatory wellness program engaging all employees within intervention work groups. The proposed workplace participatory program will assist work groups to adapt and deploy interventions that change their work environments to support healthy eating and physical activity. Nested within this group-level intervention for all workers, obese (BMI>30) workers will be offered participation in an individual-level interactive obesity treatment approach (iOTA) intervention based on assessment of individual behavior risks, collaborative goal-setting with a health coach, and use of an interactive text system to provide ongoing support and self-monitoring of behavior change goals. Investigators will test these interventions in a delayed-start group randomized trial in 22 work groups (total workers = 990, obese workers = 308).