Type of Paper: Review
Purpose: In 2008, the World Health Organization (WHO) organized a meeting on the nutrient needs and the dietary management of moderate malnutrition in children under 5 years of age. This paper was written as a background paper for the meeting and was included in the special issue on the Dietary Management of Moderate Malnutrition in the Food and Nutrition Bulletin. The purpose of this paper was to review the nutritional needs of children with moderate malnutrition and to review the foods and ingredients to treat this malnutrition.
- There is agreement in how to treat children with severe malnutrition but not on how to treat children with moderate malnutrition.
- Moderate malnutrition includes children who have z-scores between -3 and -2 according to the World Health Organization (WHO) standards (severe malnutrition is defined as z-scores below -3). Moderate malnutrition includes:
- Moderate wasting: weight-for-height between -3 and -2 z-scores.
- Moderate stunting: height-for-age between -3 and -2 z-scores.
- The prevalence of moderate malnutrition in children under 5 years old living in low income countries is as follows:
- 20% (112 million) are underweight (weight-for-age below -2 z-scores).
- 32% (178 million) are stunted (height-for-age below -2 z-scores).
- 10% (55 million) are wasted (weight-for-height below -2 z-scores).
- Moderate malnutrition, using the cutoff of -2 z-scores for the anthropometric indicators, accounts for 21% of child mortality and 21% of child disease burden. Furthermore, the majority of deaths from wasting are due to moderate wasting rather than severe wasting.
- Typical diets for malnourished populations consists of high intakes of a starchy staple, such as a cereal, with little fruits, vegetables, and legumes, and little or no animal source foods. These diets contain low densities of energy, low densities of nutrients, and limited amounts of bioavailable minerals.
- The following are important considerations for the dietary recommendations to treat moderate malnutrition:
- The nutritional needs are different in children who are malnourished compared to well-nourished children.
- The time of recovery of malnourished children depends on the type of malnutrition.
- Moderate wasting can be reversed within 2 to 4 weeks.
- Reversal of moderate stunting may take months to years and may not be reversible. Moderate stunting is easier to reverse with earlier treatment, especially if treated before 2 years of age.
Diets for Children with Moderate Malnutrition:
- General characteristics of diets for children with moderate malnutrition include:
- High content of micronutrients (especially growth nutrients)
- High energy density
- Adequate protein content
- High protein quality and availability
- Adequate fat content
- Appropriate fat quality, especially n-3/n-6 PUFA (poly-unsaturated fatty acid) content
- Content of some animal source foods
- Low content of antinutrients
- Low risk of contamination
- Acceptable taste and texture
- Culturally acceptable
- Affordable and available
- Recommendations for energy density:
- Children with moderate wasting have higher energy requirements and a higher need for energy-dense foods than children with stunting. Children with stunting probably do not need much more energy than well-nourished children.
- Stunted children: Energy densities between 1 and 1.5 kcal/g are recommended. Giving diets with high energy density to stunted children for an extended period of time could lead to obesity.
- Moderately wasted children: Energy densities between 1.5 and 2 kcal/g are recommended.
- High energy densities can be achieved by adding fats and oils to the diet. Fat content is the most important factor in increasing energy density.
- Recommendations for protein:
- Protein intake and quality is important for improving growth.
- However, too much protein in the diet may reduce the child’s appetite and is an expensive source of energy.
- High protein quality that supports maximal growth is important.
- Animal source proteins are a good source; one-third of protein intake should be from animal source foods to improve growth.
- Recommendations for fat content:
- Low fat content reduces the energy-density and total energy intake.
- Diets should contain between 35% and 45% of the energy from fat.
- When fat content is increased, the content of other nutrients also need to increase to maintain good nutrient densities.
- Recommendations for fat quality:
- The intake of PUFAs is generally low in moderately malnourished children, especially the intake of n-3 (omega 3) PUFAS compared to n-6 (omega 6) PUFAs.
- Diets should include at least 4.5% of the energy from n-6 PUFAs and 0.5% of the energy from n-3 PUfAs.
- The n-6/n-3 ratio should be less than 15 and preferably between 5 and 9.
- Foods with a high n-3 PUFA content are important. Examples include soybean oil, rapeseed oil, and fish.
- Recommendations for carbohydrates:
- Lactose intolerance is generally not a problem in moderately malnourished children. Lactose may improve mineral absorption and have prebiotic qualities.
- Starch is an important and cheap energy source.
- Dietary fiber may be harmful to moderately malnourished children. It decreases appetite and reduces nutrient and energy digestibility. Intake of insoluble fibers should be kept as low as possible in children under 2 years old.
- Recommendations for vitamins and minerals:
- The content and bioavailability of vitamins and minerals in the diets of children with moderate malnutrition is usually low and needs to be improved.
- The bioavailability of minerals is affected by other dietary components (i.e., enhancers and inhibitors).
- Phytate in foods decreases the bioavailability of minerals. Appropriate food-processing methods should be used to reduce the phytate content of foods.
- Fortification and/or supplementation with vitamins and minerals may be needed to treat moderate malnutrition.
- Recommendations for antinutrients:
- Plant-based diets have a high content of antinutrients and can have negative effects on nutrient availability and growth.
- Animal-source foods contain little or no antinutrients.
- Antinutrients to avoid include:
- Phytates are the most important antinutrient because it inhibits iron and zinc.
- Polyphenols (e.g., tannins) found in some legumes and cereals and black tea should not be given to moderately malnourished children.
- α-amylase inhibitors, protease inhibitors, lectins, saponins, and lysoalanine may have negative effects, but more research is needed.
- Cyanide, especially in cassava, should not be given.
- Recommendations for contaminants:
- Foods with a high risk of contamination need to be avoided. Aflatoxin especially should be avoided.
- Recommendations for food processing:
- Appropriate food processing, especially of staple foods, has beneficial effects.
- The outer layer of grains has a high content of both nutrients and antinutrients. Optimal milling practices will remove as much of the antinutrients as possible without removing too much of the nutrients.
- Antinutrient content is reduced by methods such as soaking, malting, and fermentation.
- Fortification with vitamins and minerals may be done during food processing.
- Specific recommendations for cereals, legumes and pulses, roots, green leafy vegetables, fruits, algae, milk, meat, eggs, fish, other animal-source foods, oils and fats, sugar, and salt are described. Please see the full text of the paper for details.
Diets used for treating moderate malnutrition should have a high content of animal-source foods (e.g., milk protein), and a low content of fiber and antinutrients. However, such diets may be expensive. Infants and children are more vulnerable to the effects of antintutrients, including phytates and insoluble fiber. Appropriate food processing methods should be used to limit the negative effects of antinutrients. Increased fat content is important for increasing energy density. Fat quality is also important in improving the diets of moderately malnourished children, and n-3 (omega 3) fatty acids need to be promoted.
Michaelsen KF, Hoppe C, Roos N, et al. Choice of foods and ingredients for moderately malnourished children 6 months to 5 years of age. Food Nutr Bull. 2009;30:S343-404.