Background: Weight stigma and bias are present in education, employment, and health care institutions, and have increased in recent years. College students in pre-health majors have been documented to hold weight biases, and interventions to mitigate these beliefs have had varying results. Objectives: This study's purpose was to assess the impact of a pedagogical intervention regarding weight stigma outcomes among first-year students. Method: Three instructors of lower-division health and social science courses implemented a 3-module lecture series on weight stigma, the environmental sources of weight variability, and body appreciation. Participants (N = 81; 48 from intervention (INT) classrooms, 33 from comparison [COM] classrooms) completed an end-of-semester survey regarding their anti-fat biases, fat phobia, and body appreciation, and a subset (n = 13) participated in a semi-structured interview about their experiences. Results: Results revealed no outcome differences between the treatment versus comparison groups, although self-reported body mass index (BMI) was a significant covariate (p = 0.008). A significant correlation emerged between BMI and fear of fat scores for COM (r = 0.52, p < 0.01) but not for INT students (r = 0.28, p > 0.05), suggesting the intervention may have impacted how students form their anti-fat biases in relation to their BMI. Qualitative findings yielded five themes -- connected course material with personal experiences; learned about weight stigma; shifted perspective on weight stigma; recognised application of weight stigma; material to future career; and valued learning about weight stigma -- that provided insight into how the intervention positively affected students. Conclusion: Informed by the findings from this study, future interventions should take a more immersive pedagogical approach.