What global maternal and child nutrition can learn from animal science
Authors: Cesar G Victora, Reynaldo Martorell, Sindura Ganapathi, R Dean Boyd, Dale E Bauman, Jack Odle
Journal: The Lancet Global Health (2017)

The main challenges to ensuring optimal nutrition of children in low-income and middle-income settings are prevention of undernutrition—including intrauterine growth restriction, stunting, and micronutrient deficiencies—and avoidance of becoming overweight.1Black RE Victora CG Walker SP et al.Maternal and child undernutrition and overweight in low-income and middle-income countries.Lancet. 2013; 382: 427-451Summary Full Text Full Text PDF PubMed Scopus (4307) Google Scholar Birth cohort studies show that linear growth in early life is associated with improved human capital (including intelligence, educational performance, and productivity) and has few, if any, deleterious effects regarding future risk of non-communicable diseases.2Adair LS Fall CH Osmond C et al.Associations of linear growth and relative weight gain during early life with adult health and human capital in countries of low and middle income: findings from five birth cohort studies.Lancet. 2013; 382: 525-534Summary Full Text Full Text PDF PubMed Scopus (521) Google Scholar By contrast, rapid weight gain, above and beyond what is required for linear growth, does not confer any benefits in terms of human capital and is associated with an increased risk of chronic diseases.2Adair LS Fall CH Osmond C et al.Associations of linear growth and relative weight gain during early life with adult health and human capital in countries of low and middle income: findings from five birth cohort studies.Lancet. 2013; 382: 525-534Summary Full Text Full Text PDF PubMed Scopus (521) Google Scholar Early undernutrition followed by exposure to an obesogenic diet in later childhood seems to result in especially poor outcomes. Ensuring that young children achieve optimal linear growth without putting on excessive weight represents a major challenge to public health and nutrition. In 1951, the British nutritionist Isabella Leitch proposed an analogy between the growth of piglets and children.3Leitch I Growth and health.Br J Nutr. 1951; 5: 142-151Crossref PubMed Scopus (79) Google Scholar Studying pigs that were undernourished early in life and then fed appropriately, she concluded that “skeleton and muscle will not grow as they would have done if they had had the opportunity at the right time, and the extra food will be used mainly to lay on fat”.3Leitch I Growth and health.Br J Nutr. 1951; 5: 142-151Crossref PubMed Scopus (79) Google Scholar She referred to these animals as “low-high”3Leitch I Growth and health.Br J Nutr. 1951; 5: 142-151Crossref PubMed Scopus (79) Google Scholar pigs, and proposed they would be better off by remaining thin than by putting on weight, arguing that this condition “can probably be prevented only by the continuation of a spartan regime throughout life, which seems a bit hard”.3Leitch I Growth and health.Br J Nutr. 1951; 5: 142-151Crossref PubMed Scopus (79) Google Scholar Whether Leitch's ideas were correct and her proposed interventions feasible, she was undoubtedly a pioneer in attempting to translate results from applied animal science to human nutrition.4Victora CG Barros FC Commentary: the catch-up dilemma—relevance of Leitch's ‘low-high’ pig to child growth in developing countries.Int J Epidemiol. 2001; 30: 217-220Crossref PubMed Scopus (65) Google Scholar Anyone who has seen or eaten pork for the past few decades will have noticed that today's animals have a larger skeletal frame and that their meat has become much leaner over time. This is partly because of breeding, but also because of precise formulation of animal diets.5National Research CouncilNutrient requirements of swine. 11th edn. The National Academy Press, Washington, DC2012Google Scholar Could new approaches to global nutrition lead to interventions that would make children grow tall without putting on excessive fat, as is the case for present-day piglets? Animal science has been addressing this issue for a long time, although with rigorous studies that cannot be conducted in humans. More than 60 years after Leitch's paper,3Leitch I Growth and health.Br J Nutr. 1951; 5: 142-151Crossref PubMed Scopus (79) Google Scholar Jack Odle and colleagues produced a landscape review6Odle J Jacobi SK Boyd RD et al.The potential impact of animal science research on global maternal and child nutrition and health: a landscape review.Adv Nutr. 2017; 8: 362-381Crossref PubMed Scopus (15) Google Scholar to address a crucial question: what can global human nutrition learn from animal science? The review covered four main areas, known in the global health literature as the continuum of care: preconception, gestation and pregnancy, lactation and suckling, and post-weaning and toddler phases. This review6Odle J Jacobi SK Boyd RD et al.The potential impact of animal science research on global maternal and child nutrition and health: a landscape review.Adv Nutr. 2017; 8: 362-381Crossref PubMed Scopus (15) Google Scholar resulted in more than a dozen key findings, suggesting some potential interventions that receive scant attention in global nutrition at present. In particular, the review highlighted “the quantitative importance of essential fatty acid and aminoacid nutrition in reproductive health; the suggested application of the ideal protein concept for improving the aminoacid nutrition of mothers and children; the prospect of using dietary phytase to improve the bioavailability of trace minerals in plant and vegetable-based diets; and nutritional interventions to mitigate environmental enteropathy”.6Odle J Jacobi SK Boyd RD et al.The potential impact of animal science research on global maternal and child nutrition and health: a landscape review.Adv Nutr. 2017; 8: 362-381Crossref PubMed Scopus (15) Google Scholar The table shows the contrast between Odle and colleagues' potential recommendations and the comprehensive list of effective diet-related interventions published in the 2013 Lancet Nutrition Series (table).7Bhutta ZA Das JK Rizvi A et al.Evidence-based interventions for improvement of maternal and child nutrition: what can be done and at what cost?.Lancet. 2013; 382: 452-477Summary Full Text Full Text PDF PubMed Scopus (1625) Google ScholarTableMain findings from Odle and colleagues' review6Odle J Jacobi SK Boyd RD et al.The potential impact of animal science research on global maternal and child nutrition and health: a landscape review.Adv Nutr. 2017; 8: 362-381Crossref PubMed Scopus (15) Google Scholar and status of interventions in global nutrition programmes7Bhutta ZA Das JK Rizvi A et al.Evidence-based interventions for improvement of maternal and child nutrition: what can be done and at what cost?.Lancet. 2013; 382: 452-477Summary Full Text Full Text PDF PubMed Scopus (1625) Google ScholarMain effects on animal healthGlobal health considerationsPreconception–conceptionEarly correction of nutrition excessNormalises fetal growth, adiposity, and glucose–insulin metabolismAt present, no emphasis on correction of overweight before conceptionCorrection of energy deficitImproves oocyte and embryo qualityEmphasis has so far been on correction of pre-conceptional underweight (through balanced energy–protein supplementation) and micronutrient deficiencies (eg, iron–folic acid and multiple micronutrients)Optimisation of essential fatty acid intakeImproves oestrus expression, conception, and maintenance of pregnancyInterventions for increasing intake of essential fatty acids are not part of global programmesGestation–pregnancyAlleviation of hyperthermiaImproves placental and fetal weight, and postnatal lean growth (more protein and less lipid)No global recommendations for reduction of exposure to heat among pregnant women, which might represent a growing problem because of climate changeOptimisation of energy and aminoacid feeding, especially to young mothers to support gestation and lactationImproves maternal tissue, fetal growth, milk production, and postnatal growthBalanced energy-protein supplementation has long been a cornerstone of maternal nutrition in poor settings, but emphasis seems to have shifted to supplementation with specific micronutrients; prevention of adolescent pregnancies and improvement of the health of adolescent girls are priority actionsOptimisation of essential aminoacid intakes by formulation of diets for so-called ideal proteinSupports protein accretion rates in conceptus and maternal tissues by preventing aminoacid deficitEmphasis on specific essential aminoacids is not an important component of global health and nutrition interventionsOptimisation of intake of functional aminoacids and fatty acidsImproves conceptus viability, development, and growthEmphasis on specific essential aminoacids is not an important component of global health and nutrition interventionsLactation–sucklingEnsuring adequate intake of quality colostrum; maternal vaccinationReduces mortality and improves intestinal health of the youngIntake of colostrum and early initiation of breastfeeding receive growing attentionIncreased fat content in lactation dietsIncreases milk fat content and neonatal growth and developmentManipulation of maternal diets to change the volume and composition of breastmilk is not part of global programmes, other than supplementary feeding for severely undernourished women during lactationOptimisation of essential aminoacid intakes by formulation of diets for so-called ideal proteinSupports milk production, growth, and development of suckling offspring, and maternal body condition by prevention of aminoacid deficitsManipulation of maternal diets to change the volume and composition of breastmilk is not part of global programmes, other than supplementary feeding for severely undernourished women during lactationJudicious supplementation with nutritionally balanced full-strength milk formulaMaintains neonatal growth when breastmilk is insufficient because of infection, agalactia, or heat stressGlobal recommendations discourage introduction of formula or animal milk, particularly before the age of 6 months, because of the increased risk of infectious diseasesPostweaning–toddlerOptimisation of essential aminoacid intakes by formulating diets for so-called ideal proteinSupports healthy lean growthAlthough nutrition counselling programmes promote the intake of high-quality animal protein, no emphasis on specific aminoacidsSupplementation of diets with phytaseImproves bioavailability of iron and zinc in plant foodsPhytase supplementation is not part of global nutrition programmesDietary medium-chain fatty acids, glutamine, arginine, plasma proteins, lactoferrin, and zincImproves aspects of intestinal health and might promote growth, especially under challenging environmental conditionsIron and zinc supplements are promoted in global programmes, but not fatty acids, aminoacids, or plasma proteins Open table in a new tab From the end of World War 2, the global community regarded protein deficiency to be the major nutritional problem in poor countries and called for policies and programmes to close the so-called protein gap. In the mid-1970s, prominent nutritionists declared this to be fallacious using terms such as “the great protein fiasco”8Semba RD The rise and fall of protein malnutrition in global health.Ann Nutr Metab. 2016; 69: 79-88Crossref PubMed Scopus (83) Google Scholar and world attention shifted from protein quantity and quality, to quantity of food. More recently, the concern with quality returned but with a focus on micronutrients. The first major difference with respect to animal research is the extent to which human programmes today focus on micronutrients. At different stages during the continuum of care, global nutrition relies on promotion of intake of folic acid, iron, calcium, iodine, vitamin K, vitamin A, and multiple micronutrient supplements. By contrast, animal studies give more comprehensive attention to macronutrients, such as specific aminoacids and fatty acids, which are not considered at all in global human nutrition programmes. Even programmes that promote nutrition counselling with use of locally grown foods or provision of protein-energy supplements do not focus on specific macronutrients. Odle and colleagues6Odle J Jacobi SK Boyd RD et al.The potential impact of animal science research on global maternal and child nutrition and health: a landscape review.Adv Nutr. 2017; 8: 362-381Crossref PubMed Scopus (15) Google Scholar emphasise that, in the case of protein and fat, it is crucial to consider both the quantity provided by the diet as well as the pattern of essential aminoacids and fatty acids ingested. They further declare that “the basic information needed to formulate diets to meet aminoacid needs in humans represents a serious gap in knowledge”,6Odle J Jacobi SK Boyd RD et al.The potential impact of animal science research on global maternal and child nutrition and health: a landscape review.Adv Nutr. 2017; 8: 362-381Crossref PubMed Scopus (15) Google Scholar unlike animal science where aminoacid patterns resulting in ideal proteins are well described and widely used.5National Research CouncilNutrient requirements of swine. 11th edn. The National Academy Press, Washington, DC2012Google Scholar, 6Odle J Jacobi SK Boyd RD et al.The potential impact of animal science research on global maternal and child nutrition and health: a landscape review.Adv Nutr. 2017; 8: 362-381Crossref PubMed Scopus (15) Google Scholar This is not to imply that micronutrient supplementation does not have a major place in global nutrition. Indeed, animal studies are strongly supportive, for example, of zinc supplementation to prevent environmental enteropathy leading to growth failure. What strikes us is how concerns with micronutrients might have distracted attention from consideration of essential macronutrients and the interplay between micronutrient and macronutrient deficiencies that commonly exist in low-income and middle-income countries. Odle and colleagues6Odle J Jacobi SK Boyd RD et al.The potential impact of animal science research on global maternal and child nutrition and health: a landscape review.Adv Nutr. 2017; 8: 362-381Crossref PubMed Scopus (15) Google Scholar also suggest some innovative potential interventions in areas that are unexplored in global nutrition. Temperature control, widely used in animals to avoid heat stress, is not mentioned in global programmes. Admittedly, temperature control is difficult to implement at large scale in a cost-effective manner. Dietary microaddition of phytase aimed at destruction of phytic acid, a powerful antinutrient, is also worthy of further exploration in global nutrition. Regarding lactation, maternal supplementation to modulate the quantity and quality of human milk has received little attention in global health, as there is a common assumption that the quality of breastmilk is relatively constant even among undernourished mothers, and that these women are able to produce enough milk. By stark contrast, such interventions are widely used in animal science, with well-documented effects on milk quality and quantity, and a striking effect on litter growth. Animal scientists sometimes use formula to supplement breastmilk if there is evidence of growth faltering. By contrast, the risk of infections and mortality led the global nutrition community to strongly discourage the use of formula and feeding bottles in early infancy. Renewed attention to maternal diets might help improve infant growth in the first 6 months of life, when exclusive breastfeeding is essential for preventing infections, yet growth faltering is already taking place.9Victora CG de Onis M Hallal PC Blössner M Shrimpton R Worldwide timing of growth faltering: revisiting implications for interventions.Pediatrics. 2010; 125: e473-e480Crossref PubMed Scopus (899) Google Scholar Animal scientists have been remarkably successful in reducing mortality and growth faltering in controlled breeding situations, and in producing animals that are lean and achieve their full growth potential. Global nutrition has much to learn in this respect. Not all interventions will be effective, feasible, or even desirable for humans. Furthermore, neurocognitive outcomes—a priority for global child health—are not assessed in animal science. However, robust findings from the long history of experimentation in animal science suggest that the time for some lateral thinking in global nutrition is long overdue. JO reports grants from the Bill & Melinda Gates Foundation during the conduct of the study. All other authors declare no competing interests.