Primary care providers (PCPs) can empower their patients to make health-promoting behavior changes. Many guidelines recommend that PCPs counsel overweight and obese patients about weight loss, yet few studies examine the impact of provider weight loss counseling on actual changes in patient behavior. We performed a systematic review and meta-analysis of published studies of survey data examining provider weight loss counseling and its association with changes in patient weight loss behavior. We reviewed the published literature using keywords related to weight loss advice. We used meta-analytic techniques to compute and aggregate effect sizes for the meta-analysis. We also tested variables that had the potential to moderate the responses. A total of 32 studies met criteria for the literature review. Of these, 12 were appropriate for the meta-analysis. Most studies demonstrated a positive effect of provider weight loss advice on patient weight loss behavior. In random effects meta-analysis, the overall mean weighted effect size for patient weight loss efforts was odds ratio (OR)=3.85 (95% confidence interval (CI) 2.71, 5.49; P<0.01), indicating a statistically significant impact of weight loss advice. There was no significant difference in the effectiveness of advice in studies using obese patients alone versus mixed samples (obese alone OR=3.44, 95% CI 2.37, 5.00; mixed sample OR=3.98, 95% CI 2.53, 6.26, P=0.63). PCP advice on weight loss appears to have a significant impact on patient attempts to change behaviors related to their weight. Providers should address weight loss with their overweight and obese patients.