Describing the triple burden of malnutrition in adolescents in rural and urban South Africa

Objectives: To describe the triple burden of malnutrition among a large, school-going sample of adolescents in rural Agincourt and urban Soweto, South Africa.Design: Cross-sectional study.Setting: Schools and community centres across rural Agincourt and urban Soweto, South Africa.Subjects: 12 644 adolescents (mean age 15.5 years; 62% girls; 70.7% rural).Measures: International Obesity Task Force cut-offs were used to calculate the prevalence of underweight, healthy weight, overweight, and obesity. Haemoglobin levels were measured in Soweto to assess the prevalence of anaemia.Results: This large, population-based study reveals a high burden of malnutrition, with 34.9% of adolescents either underweight, overweight, or obese. Underweight prevalence was 14.3%, with relatively uniform distribution across sex and setting. Overweight and obesity were notably more prevalent in urban girls (32.3% and 7.0%, respectively), nearly doubling the rates observed in their rural peers (17.4% and 5.8%), and substantially higher than urban and rural boys (all < 6%). Boys consistently exhibited lower body fat percentage and fat mass index compared with girls across both settings. In a subsample of urban adolescents with haemoglobin data, anaemia was common, particularly in girls (31.6% vs. 10.2% in boys).Conclusions: These findings highlight the complexity of the burden of malnutrition in adolescence, including both under- and over-nutrition with overlapping micronutrient deficiencies.