Perceived Body Mass Index, Body Image and Weight Control Behaviours among University Students in Johannesburg

Abstract

This study investigates the relationship between body mass index (BMI), body image, and weight control behaviours (WCBs) among university students in Johannesburg, South Africa. According to a 2012 national nutrition report, 40.9% of South Africans were classified as obese, while the country also ranked fourth globally in eating disorder–related mortalities. These figures underscore the paradoxical coexistence of obesity and disordered eating within the same society, making South Africa a critical site for exploring how body ideals and practices are negotiated. Historically, larger bodies symbolised health, fertility, and prosperity in African contexts; however, processes of urbanisation, globalisation, and social media exposure have shifted ideals toward slenderness, curves, and muscularity. Universities represent an important context for examining these tensions, as students navigate independence, peer influence, and emerging adult identities while situated in environments that promote obesity. The study employed a mixed-methods design, combining quantitative surveys (n = 46) and qualitative in-depth interviews (n = 8) with students at the University of the Witwatersrand. Quantitative data were analysed using SPSS to assess associations between BMI, sex, socioeconomic status (SES), media exposure, family and peer influence, and body image perceptions. Thematic analysis of interviews in ATLAS. ti provided deeper insights into how students internalise, negotiate, and resist body ideals. Findings revealed striking gaps between actual BMI and perceived body size. Many students with normal BMI overestimated their weight and engaged in WCBs to lose weight. Others pursued WCBs mainly for aesthetic or social reasons. Contrary to much existing literature, sex and SES were not significantly associated with BMI. Instead, family and peer commentary influenced dissatisfaction and behaviours more than media exposure. Social media platforms like Instagram and TikTok subtly reinforced aspirational norms. Students articulated competing ideals. Some aligned with the ideals of thinness or muscularity prevalent in high-income societies. Others aspired to hybrid "slim-thick" body types, reflecting the negotiation between traditional African values and globalised beauty standards. The study makes three key contributions to the field of body image and health research. First, it challenges the adequacy of BMI as a single measure of health. Dissatisfaction and WCBs extended across BMI categories. Second, it shows that interpersonal and cultural pressures outweigh biomedical framings in shaping body image. Third, it illustrates gendered renegotiation of ideals. Overall, the findings support moving beyond weight-centric discourses. There is a need for socioculturally informed approaches to body image and health in urban African contexts.