Food and Nutrition Bulletin

With a fast-approaching post-Millennium Development Goal era, there is an urgent need to boost global investment in efforts to reduce child malnutrition. Critical to the management of moderate malnutrition, and therefore to the new Sustainable Development Goals, is addressing severe acute malnutrition (SAM) and moderate acute malnutrition (MAM). Despite the considerable difference in the approximate number of children affected by MAM (33 million) compared with SAM (19 million), there is currently no standardized approach to the management of MAM. In partnership with Valid International, the World Food Programme, and the Micronutrient Initiative, the International Atomic Energy Agency hosted the International Symposium on Understanding Moderate Malnutrition in Children for Effective Interventions in Vienna, Austria, 26–29 May 2014. This symposium focused on the management (prevention and treatment) of MAM in children. The symposium convened over 350 participants from 63 countries, the majority of whom represented governments responding to moderate malnutrition in their populations, nearly 70 national and international organizations from the United Nations and nongovernmental sectors, and universities from around the world, as well as donor governments and private-sector entities. The symposium was structured around nine sessions over a 3-day period, progressing from a global analysis of the scale of the problem to recent research findings relevant to designing effective interventions. This Supplement contains a series of papers that summarize the symposium sessions and other fundamental aspects important to improving the management of moderate malnutrition in children.

Wasting and stunting are often presented as two separate forms of malnutrition requiring different interventions for prevention and/or treatment. These two forms of malnutrition, however, are closely related and often occur together in the same populations and often in the same children. Wasting and stunting are both associated with increased mortality, especially when both are present in the same child. A better understanding of the pathophysiology of these two different forms of malnutrition is needed to design efficient programs. A greatly reduced muscle mass is characteristic of severe wasting, but there is indirect evidence that it also occurs in stunting. A reduced muscle mass increases the risk of death during infections and also in many other different pathological situations. Reduced muscle mass may represent a common mechanism linking wasting and stunting with increased mortality. This suggests that to decrease malnutrition-related mortality, interventions should aim at preventing both wasting and stunting, which often share common causes. Also, this suggests that treatment interventions should focus on children who are both wasted and stunted and therefore have the greatest deficits in muscle mass, instead of focusing on one or the other form of malnutrition. Interventions should also focus on young infants and children, who have a low muscle mass in relation to body weight to start with. Using mid-upper-arm circumference (MUAC) to select children in need of treatment may represent a simple way to target young wasted and stunted children efficiently in situations where these two conditions are present. Wasting is also associated with decreased fat mass. A decreased fat mass is frequent but inconsistent in stunting.

Fat secretes multiple hormones, including leptin, which may have a stimulating effect on the immune system. Depressed immunity resulting from low fat stores may also contribute to the increased mortality observed in wasting. This may represent another common mechanism linking wasting and stunting with increased mortality in situations where stunting is associated with reduced fat mass. Leptin may also have an effect on bone growth. This may explain why wasted children with low fat stores have reduced linear growth when their weight-for-height remains low. It may also explain the frequent association of stunting with previous episodes of wasting. Stunting, however, can occur in the absence of wasting and even in overweight children. Thus, food supplementation should be used with caution in populations where stunting is not associated with wasting and low fat stores.

Acute malnutrition is associated with increased morbidity and mortality risk. When episodes are prolonged or frequent, acute malnutrition is also associated with poor growth and development, which contributes to stunting. Nutrition-specific and nutrition-sensitive strategies to prevent undernutrition during the first 1,000 days from conception to 24 months of age can reduce the risks of wasting, stunting, and micronutrient deficiencies. Under circumstances that exacerbate the underlying causes of undernutrition and increase the incidence of wasting, such as food insecurity related to lean seasons or emergencies, or increased incidence of illness, such as diarrhea or measles, additional efforts are required to prevent and treat wasting. Special nutritious foods directly meet the increased nutrient requirements of children at risk for wasting; assistance to vulnerable households, in the form of cash or food, enables households to better meet the food, health, and other needs of household members and may increase resilience; water, sanitation, and hygiene (WASH) and health interventions help prevent and address illness and hence reduce wasting risk. The contributions of specific interventions to reducing the incidence of wasting are difficult to assess under emergency conditions, due to ethical constraints and to the fact that multiple strategies are implemented at the same time. However, pragmatic studies under real-life circumstances, using different designs, e.g., including a group receiving “best possible” treatment, can provide evidence about what works, to what extent, at what cost, and under which circumstances. Programs should address the most important causes in given contexts, be feasible to implement at scale, and assess implementation, coverage, and outcomes.

There is a need for trials on the effects of food aid products for children with moderate acute malnutrition, to identify how best to restore body tissues and function. The choice of control intervention is a major challenge, with both ethical and scientific implications. While randomized trials are needed, special designs, such as cluster-randomized, stepped-wedged or factorial designs may offer advantages. Anthropometry is widely used as the primary outcome in such trials, but anthropometric traits do not refer directly to specific organs, tissues, or functions. Thus, it is difficult to understand what components of health might be impacted by public health programs, or the underlying mechanisms whereby improved nutritional status might benefit short- and long-term health. Measurement of body composition, specific growth markers and functional outcomes may provide greater insight into the nature and implications of growth failure and recovery. There are now several methodologies suitable for application in infants and young children, e.g., measuring body composition with deuterium dilution, physical activity with accelerometers and linear growth with knemometers. To evaluate the generalizability of the findings from nutrition trials, it is important to collect data on baseline nutritional status.

Evidence from low- and middle-income countries indicates that although there is a willingness to prevent and treat malnutrition at scale, there is very limited capacity to achieve this. Three broad areas of concern are human resources and the quality of services; management systems and supplies; and demand side factors. This paper focuses on building human resources in the context of preventing and managing malnutrition. Training should provide several options and approaches suitable for different settings and focus on core competencies. Preservice training should be the main focus of training, while in-service training should be used for continuing medical education and refresher training. Communities of Practice, in which national and international health professionals come together to deepen their knowledge and pool their skills to pursue a common ambition, are seen as one way forward to building the necessary human resources for scaling up training.

Ready-to-use therapeutic foods (RUTFs) are solid foods that were developed by changing the formulation of the existing liquid diet, F-100, recommended by the World Health Organization (WHO) for the rapid catch-up phase of the treatment of children suffering from severe acute malnutrition (SAM). The resulting products proved highly effective in promoting weight gain in both severely and moderately wasted children and adults, including those infected with HIV. The formulation of the existing RUTFs, however, has never been optimized to maximize linear growth, vitamin and mineral status, and functional outcomes. The high milk content of RUTFs makes it an expensive product, and using lower quantities of milk seems desirable. However, the formulation of alternative, less expensive but more effective versions of RUTF faces difficult challenges, as there are uncertainties regarding the effect in terms of protein quality, antinutrient content, and flatulence factors that will result from the replacement of current dairy ingredients by less expensive protein-rich ingredients. The formulation of alternative RUTFs will require further research on these aspects, followed by efficacy studies comparing the future RUTFs to the existing formulations.

Ready-to-use foods are one of the available strategies for the treatment of moderate acute malnutrition (MAM), but challenges remain in the use of these products in programs at scale. This paper focuses on two challenges: the need for cheaper formulations using locally available ingredients that are processed in a safe, reliable, and financially sustainable local production facility; and the effective use of these products in large-scale community-based programs.

Linear programming tools can be used successfully to design local compositions that are in line with international guidelines, low in cost, and acceptable, and the efficacy of these local formulations in the treatment of MAM was recently demonstrated in Malawi.

The production of local formulations for programs at scale relies on the existence of a reliable and efficient local production facility. Technical assistance may be required in the development of sustainable business models at an early stage in the process, taking into account the stringent product quality and safety criteria and the required investments.

The use of ready-to-use products, as of any food supplement, in programs at scale will be affected by the practice of household sharing and diversion of these products for other uses. Additional measures can be considered to account for sharing. These products designed for the treatment and prevention of MAM are to be used in community-based programs and should therefore be used in conjunction with other interventions and designed so that they do not replace the intake of other foods and breastmilk. Remaining challenges and implications for the (operations) research agenda are discussed.

A need for improved empirical evidence for the effectiveness of interventions used in the management of child wasting (moderate and/or severe acute malnutrition) has recently been highlighted. There is no lack of published studies in this field, but when examined through the lens of systematic review protocols, few of these studies stand up to rigorous methodological critique. This paper summarizes the current state of knowledge, as supported by high-quality research included in multiple systematic reviews. It also elaborates on the criteria and standards used in such reviews. The paper highlights the weaknesses of many studies that could, with more care during study design and reporting, result in a larger body of evidence being available to policy makers and program implementers dealing with child wasting.

A pattern of changes in the microbiome composition have been observed in the normal maturation of the human gut. Perturbations from this pattern have been described in malnourished humans and reproduced in animal models of severe malnutrition. Treatment and prevention of malnutrition in the future may be more effective if the interventions not only restore body composition, but the composition of the microbiome as well.