Most countries, at all levels of development, experience multiple forms of malnutrition.1 The coexistence of nutritional deficiencies and overweight or obesity and associated diet-related non-communicable diseases (DR-NCDs)—ie, the double burden of malnutrition (DBM)—is observed within communities, households, and individuals.2 In high-income countries, where overweight and obesity affects more than half of the population, food insecurity among people with low incomes manifests as low-quality diets often dominated by high consumption of foods, snacks, and beverages high in energy, sugar, fat, and salt.3 These diets lead to excessive intakes of energy, DR-NCDs, and deficiencies in protein and essential micronutrients such as iron, folate, vitamins B6, B12, C, D, and calcium.4, 5 At the other extreme, low-income and middle-income countries (LMICs) still struggling with persistent problems of maternal undernutrition, child stunting and wasting, and widespread micronutrient deficiencies are having a rapid rise in overweight and obesity at lower levels of national income than previously seen.2
The DBM presents new challenges for policy and programming. In LMICs, national nutrition policies and donor funding have historically focused on undernutrition. Yet there is no longer just undernutrition, but also overweight, obesity, and DR-NCDs to deal with. There has been increasing global recognition that all types of malnutrition need to be addressed (panel 1). Target 2.2 of the Sustainable Development Goals is to “end malnutrition in all its forms”12 and the Lancet Commission on the global syndemic of obesity, undernutrition, and climate change highlights the need to tackle these interconnected problems simultaneously.19
Nevertheless, actions to address the different manifestations of malnutrition are still isolated from each other and implemented through different governance and funding mechanisms (panel 1). Studies over a decade ago raised the concern that taking a siloed approach to tackling food insecurity and undernutrition could do harm to obesity,20 and miss opportunities to use the same platforms for shared action.16
Key messages
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Actions to address undernutrition, and overweight and obesity have historically been developed and delivered separately from one another. Some evidence shows that programmes addressing undernutrition have unintentionally increased risks for obesity and diet-related non-communicable diseases (DR-NCDs) in low-income and middle-income countries where food environments are changing rapidly. Yet policies and interventions to address undernutrition typically fail to consider these risks.
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By contrast, double-duty actions aim to simultaneously prevent or reduce the risk of both nutritional deficiencies leading to underweight, wasting, stunting or micronutrient deficiencies, and obesity or DR-NCDs, with the same intervention, programme, or policy.
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Double-duty actions are based on the rationale that all forms of malnutrition share common drivers that can be leveraged for double impact. These drivers include early life nutrition, diet diversity, food environments, and socioeconomic factors.
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The available evidence indicates that there are ten strong candidates for double-duty actions across different sectors. These actions include interventions delivered through health services, social safety nets, educational settings, agriculture, food systems, and food environments
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Putting a double-duty approach into operation involves assessing the potential harm of existing actions and redesigning programmes and policies with a focus on double-duty actions. Changes in governance, financing, and capacity building will be needed to put the approach to use.
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Double-duty actions are urgently needed as part of a holistic approach to ending malnutrition in all its forms by 2030.
The objective of this Series paper is to explore the potential for a more holistic approach to address the DBM. Double-duty actions, a term coined in the 2015 Global Nutrition Report,13, 18 are interventions, programmes, and policies that simultaneously prevent or reduce the risk of both nutritional deficiencies leading to underweight, wasting, stunting and micronutrient deficiencies, and problems of obesity and DR-NCDs. Instead of narrowly focusing on one problem at a time, these actions aim to maximise the benefits of taking action on one form of nutrition for another, and minimise the risks of any form of malnutrition.21, 22 The term triple duty has also been used to refer to actions that address additional development problems, such as climate change.18, 23
This Series paper answers the call to identify priority double-duty actions.18 It does so, firstly, by setting out the rationale for double-duty actions (that different forms of malnutrition share common drivers) and using this evidence to develop a simple framework of the factors that need to be considered when designing actions to address more than one form of malnutrition. Second, using this framework as a guide, we review the literature to identify existing evidence that actions focused on undernutrition introduce risks or cause harm for obesity and DR-NCDs (see appendix pp 2–4 for method); and third, we identify the opportunities to retrofit existing, established actions focused on undernutrition to also address obesity and non-communicable diseases.21 The Series paper ends by setting out the next steps for using the double-duty approach and identifying research priorities.
