Weight underestimation and high cardiovascular disease risk among South African adults with obesity: implications for integrated obesity prevention.

Background: The contribution of body size perception to cardiovascular disease risk among persons with inherent negative body image perceptions in African settings has not been established. This study describes body image, weight discordance and absolute 10-year CVD risk score among predominantly obese black South African adults.

Methods: A cohort study involving 920 adults aged 35-78 years in an urban township, a rural community, and South Africa. Medical history, anthropometrics and blood pressure were taken at baseline and follow-up. Body image perceptions were obtained using a validated body shape questionnaire at follow-up, and each participant's absolute 10-year CVD risk scores were also determined. Descriptive and mean comparison analyses were undertaken using SPSS version 26.

Results: A higher proportion of women (84.1%) compared to men (32.2%) were overweight (BMI > 25 kg/m²). Increasing weight underestimation was associated with relative weight gain in both genders. Body weight underestimation had a weak, significant association with 10-year absolute CVD risk scores. About a quarter of men, compared to 58.3% of women, 42% of those with normal weight, and 30% with obesity, had a 'high' 10-year CVD risk score (i.e. score ≥ 20%). In both the urban (62% vs. 30%) and the rural (53% vs. 20%) communities, men had higher CVD risk scores than women, and these comparisons were statistically significant (p < 0.05).

Conclusion: Obesity and CVD risk prevention programmes targeting black South Africans should consider a sustained healthy weight maintenance intervention focusing on personalised self-assessments of weight gain intentions and body size preferences.