The Think Health! study evaluated a behavioral weight loss program adapted from the Diabetes Prevention Program (DPP) lifestyle intervention to assist primary care providers (PCPs) and auxiliary staff acting as lifestyle coaches (LCs) in offering weight loss counseling to their patients. In a randomized trial conducted at five clinical sites, study participants were randomly assigned in a 1:1 ratio within each site to either "Basic Plus" (n = 137), which offered PCP counseling every 4 months plus monthly LC visits during the first year of treatment, or "Basic" (n = 124), which offered only PCP counseling every 4 months. Participants were primarily (84%) female, 65% African American, 16% Hispanic American, and 19% white. In the 72% of participants in each treatment group with a 12-month weight measurement, mean (95% CI) 1-year weight changes (kg) were -1.61 (-2.68, -0.53) in Basic Plus and -0.62 (-1.45, 0.20) in Basic (difference: 0.98 (-0.36, 2.33); P = 0.15). Results were similar in model-based estimates using all available weight data for randomized participants, adjusting for potential confounders. More Basic Plus (22.5%) than Basic (10.2%) participants lost ≥ 5% of their baseline weight (P = 0.022). In a descriptive, nonrandomized analysis that also considered incomplete visit attendance, mean weight change was -3.3 kg in Basic Plus participants who attended ≥ 5 LC visits vs. + 0.53 kg in those attending <5 LC visits. We conclude that the Basic Plus approach of moderate-intensity counseling by PCPs and their staff can facilitate modest weight loss, with clinically significant weight loss in high program attenders.