Purpose: This study explores how social support and social norms influence Black and Hispanic adults' experience in a weight management program, and if this varies based on race, ethnicity, and gender. Approach: Semi-structured interviews and egocentric social network assessments. Setting: Single primary care site in New York City. Participants: Twenty Black and Hispanic adults in a weight management program. Method: Interviews explored social influences on weight loss and differences based on demographics. Network composition and functions were characterized through social network analyses. Results: Participants favored informational and tangible support to achieve health goals, through shared experiences and assistance, but felt social gatherings and unhealthy dietary norms undermined behavior change. Females described emotional strain, weight stigma, and the burden of balancing multiple social roles, whereas males emphasized health-related motivations and cultural dietary challenges. Among 276 network members identified, females tended to disclose program participation to friends, while males tended to disclose participation to people that provided them with health advice. Variability in social influence types and sources was primarily associated with gender, not race or ethnicity. Conclusions: Social influences potentially play an important role in Black and Hispanic adults' engagement in a weight management program, with notable gender differences. Incorporating social network members to facilitate specific forms of support and overcome unique social pressures may enhance the effectiveness of weight loss interventions.