This study is a two-group clustered randomized trial to evaluate if improving child care providers' health behaviors elicit meaningful change in dietary and physical activity behaviors in 2-5-year-old preschool children in their care and the child care environment. The investigators will randomize (by center, 1:1 ratio) 84 child care centers, 168 child care providers, and 672 children from these centers to one of two groups (standard Go NAPSACC or Go NAPSACC enhanced) for a 12 month trial (6 months provider weight loss; 6 months no contact follow-up). The specific aims are to 1) improve dietary quality and physical activity behaviors of 2-5-year-old children. 2) improve weight and weight related behaviors (dietary intake and physical activity) of child care providers, and 3) improve the nutrition and physical activity environments at child care centers. Participants randomized to standard Go NAPSACC will receive support for center wide changes focusing on engaging center directors and orienting them to Go NAPSACC, given access to interactive online tools that guide change, and providing ongoing support as they work to adopt evidence-based healthy weight practices. Participants randomized to Go NAPSACC enhanced will receive the traditional Go NAPSACC program (previously described); in addition, child care providers will receive a weight management intervention. The weight management intervention will be guided by social cognitive theory and integrate techniques known to be most effective for changing diet and physical activity behaviors, including intention formation, goal setting (≥5% weight loss at 6 mos. and no regain at 12 mos.), self-monitoring (diet, physical activity, weight), and feedback. Participants will receive a progressive physical activity program. The physical activity program (walking, jogging, biking, etc.) will be progressive and prescribed at a moderate intensity as recommended the "Physical Activity Guidelines for Americans" of 150 min/wk. Starting active minutes goal will be based on self-reported current activity levels: 0 min/wk = 10 min/day goal; 1-59 min/wk = 15/min/day goal, \>60 min/wk = 20 min/day goal. The reduced energy diet will follow the Stop Light Diet approach which categorizes foods by energy content: green (low energy: consume freely), yellow (moderate energy: consume in moderation) and red (high energy: consume sparingly). Starting weight will be used to suggest tailored red food limits: Weight Loss - \<250lbs = 3; 250 - \<300 = 4; \>300 = 5. Weight Maintenance - \<250 = 4; 250 - \<300 = 5; \>300 = 6. The stop light diet approach is suitable for all participants (including for whom weight loss may not be recommended \[e.g., BMI \<25 kg/m2\] as it does not specifically prescribe a calorie deficit but focuses on improvement of diet quality.The effectiveness of the intervention will be evaluated by comparing differences between the Go NAPSACC enhanced and standard Go NAPSACC control groups in child's physical activity and diet quality at 6 mos. (primary outcomes). Primary and secondary aims will be analyzed using maximum likelihood methods. Multi-level linear mixed models with repeated measures will be used to estimate change at 6 and 12 mos. and to test for statistical differences across groups in changes over time. Models will include random effect for cluster to account for covariance between participants within the same center as well as fixed effects for time, trial arm, time\*arm interaction. To further explore the effect of the intervention, these analyses will be followed by sensitivity analyses that adjust for baseline variables distributed differently between intervention groups and examine completers only. Secondary outcomes will also be examined as longitudinal covariates and asses their association with longitudinal measures of primary outcomes, controlling for treatment, at 6 and 12 months.