Given the epidemic of obesity, approaches to weight loss that can be applied on a community, state, or national level are needed. We report results from Shape Up Rhode Island 2007 (SURI), a statewide Internet-based program involving team-based competition to increase physical activity and achieve weight loss. A total of 4,717 adults (84% women; mean BMI = 29.6 kg/m(2)) enrolled in the 16-week weight loss competition of SURI and 3,311 completed at least 12 weeks. Completers reported losing 3.2 +/- 3.4 kg, and 30% achieved a clinically significant weight loss of >or=5%. Although modest, these weight losses shifted the BMI distribution from a mean BMI of 29.4 to a mean of 28.2 kg/m(2) and reduced the population that was obese from 39 to 31%. More conservative intent-to-treat analyses and analysis of 132 participants with objective weights still showed a significant reduction in BMI of -0.8 units. These findings suggest that statewide weight loss campaigns can produce modest weight losses in large numbers of participants. These data provide a benchmark that can be used for comparisons with other statewide campaigns. Research on ways to improve such campaigns is needed.