Background:
Low- and middle-income countries (LMICs) experiencing nutrition transition face an increasing double burden of malnutrition (DBM). The World Health Organization has urged the identification of risks and opportunities in nutrition interventions to mitigate the DBM, but robust evidence is missing. This review summarises the impact of nutrition-specific and nutrition-sensitive interventions on under- and overnutrition simultaneously in LMICs.
Methods:
We searched four major databases and grey literature for publications in English, French, Portuguese, and Spanish from January 1, 2000, to August 14, 2023. Eligible studies evaluated nutrition-specific and/or nutrition-sensitive interventions on both under- and overnutrition, employing robust study designs (individually-, cluster- and non-randomised trials, interrupted time series, controlled before-after and prospective cohort studies). Studies were synthesised narratively, and classified as DBM-beneficial, potentially DBM-beneficial, DBM-neutral, potentially DBM-harmful, and DBM-harmful, using vote counting. The review is registered with PROSPERO, CRD42022320131.
Findings:
We identified 26 studies evaluating 20 nutrition-specific (maternal and child health (MCH) and school-based programmes) and six nutrition-sensitive interventions (conditional cash transfers and other social policies). Seven out of eight MCH interventions providing food-based or nutritional supplements indicated possible DBM-harmful impacts, associated with increased maternal or child overweight. Most school-based programmes and behavioural change MCH interventions were considered potentially DBM-beneficial. Two evaluations of conditional cash transfers suggested DBM-beneficial impacts in children, while one indicated potentially harmful effects on maternal overweight. Evaluations of a family planning service and an education reform revealed possible long-term harmful impacts on obesity.
Interpretation:
There is considerable scope to repurpose existing nutrition interventions to reduce the growing burden of the DBM in LMICs. In settings undergoing rapid nutrition transition, specific policy attention is required to ensure that food- or supplement-based MCH programmes do not unintentionally increase maternal or child overweight. Consistent reporting of under- and overnutrition outcomes in all nutrition interventions is essential to expand the evidence base to identify and promote interventions maximising benefits and minimising harms on the DBM.
Funding:
President's Scholarship (Imperial College London) and National Institute for Health and Care Research (NIHR).