Intervention to optimise body mass index in adolescents and address the triple burden of malnutrition—the Ntshembo (Hope) trial in rural and urban South Africa study: a study protocol for a randomised controlled trial

TL;DR

This study aims to improve nutrition and BMI in South African adolescent girls to reduce long-term health risks through a community-based intervention.

Contribution

A novel community-based intervention targeting the triple burden of malnutrition in adolescent girls in South Africa.

Findings

The trial will assess BMI changes in underweight and overweight adolescent girls.

Intervention includes household support, micronutrient supplements, and health education.

Abstract

South Africa faces a complex health burden with burgeoning non-communicable diseases against a background of prevalent infection. The triple burden of malnutrition, comprising undernutrition alongside overweight/obesity and micronutrient deficiencies, is widespread and imposes risks for non-communicable diseases along the life course, especially among adolescent girls. We hypothesise that, by optimising nutrition and body mass index (BMI) of at-risk adolescent girls, we can realise a triple return on investment: improved nutritional status, reduced metabolic risk, and moderated pre-conception exposures to offset transgenerational risk for cardiometabolic disease.

We will enrol 1248 girls 14–19 years with either underweight or overweight defined using age-sex-appropriate BMI cut-offs living either in rural or urban South Africa. After baseline assessments and randomisation, participants will be reassessed at 18–24 months follow-up. If a participant becomes pregnant, further assessments will be conducted during pregnancy (< 28 weeks) and postnatally. We will include both process and economic evaluations. The primary outcome is change in BMI standard deviation score from baseline to follow-up aligned to the target direction, i.e. increase in BMI for underweight, decrease in BMI for overweight. Community health workers will deliver the intervention with both household and individual components. A conditional cash transfer will be provided to the household with guidance to improve dietary diversity. Health literacy material, a multi-micronutrient supplement, health screening and support management (for example anaemia; blood pressure; HIV; depression), and facilitating behaviour change to optimise nutrition, physical and mental health will be provided to the adolescent girl.

The trial has been registered with the Pan African Clinical Trials Registry; identifier: PACTR202201638897606. Registered on 1st August 2022. https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=14656.

The online version contains supplementary material available at 10.1186/s13063-026-09535-4.

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