Nutrition Publication

Childrens’ Nutritional Needs and Realities in an Emerging World

Editor(s): E. Nel. Vol.72 / 2

Children in developing countries are faced with many nutritional challenges. On the one hand, food security is under threat with inadequate energy intake and low dietary diversity; on the other hand, children are often exposed to diets typical of a Western lifestyle, leading to obesity and its attendant complications. This double burden of malnutrition is increasingly recognised in developing countries, particularly those in sub-Saharan Africa.Recently, studies have highlighted the poor intake of school children and adolescents and the potential that interventions in this age group may have to improve growth and development.In this issue of Annals of Nutrition and Metabolism, we address some of these questions (trends in childhood stunting and adulthood obesity, vitamin D and calcium metabolism, dietary intake in schoolchildren and adolescents, and the role of mycotoxins) with an emphasis on Africa.

Related Articles

Africa in Transition Growth Trends in Children and Implications for Nutrition

Author(s): S. Norris, S. Wrottesley, R. Mohamed, L. Micklesfield

The aims of this paper were to: (1) review the literature and examine contemporary child growth in terms of stunting prevalence across Africa; (2) discuss child stunting within the context of economic growth and adult obesity, and (3) elucidate the implications for child nutrition. It is evident that stunting in under-5-year-old children still plagues Africa and has not decreased as expected in line with the concomitant improvement in economic development over the past de-cade. Persisting and possibly widening inequality ensures that not all segments of the population, in particular the most vulnerable, benefit equally from economic growth. Of concern is the association between the increasing economic progress across Africa and the rising adult obesity, especially amongst females. More and more African countries are now afflicted with a double burden of malnutrition. The implication for child nutrition is that African countries need not only apply a multisectoral approach to accelerate the reduction in stunting levels, but also to arrest and prevent obesity.

Calcium and Vitamin D Metabolism in Children in Developing Countries

Author(s): J. Pettifor

Low dietary calcium intakes and poor vitamin D status are common findings in children living in developing countries.Despite many of the countries lying within the tropics and subtropics, overcrowding, atmospheric pollution, a lack of vitamin D-fortified foods, and social customs that limit skin exposure to sunlight are major factors in the development of vitamin D deficiency. Low dietary calcium intakes are typically observed as a consequence of a diet limited in dairy products and high in phytates and oxalates which reduce calcium bioavailability. Calcium intakes of many children are a third to a half of the recommended intakes for children living in developed countries, yet the consequences of these low intakes are poorly understood as there is limited research in this area. It appears that the body adapts very adequately to these low intakes through reducing renal calcium excretion and increasing fractional intestinal absorption. However, severe deficiencies of either calcium or vitamin D can result in nutritional rickets, and low dietary calcium intakes in association with vitamin D insufficiency act synergistically to exacerbate the development of rickets. Calcium supplementation in children from developing countries slightly increases bone mass, but the benefit is usually lost on withdrawal of the supplement. It is suggested that the major effect of calcium supplementation is on reducing the bone remodelling space rather than structurally increasing bone size or volumetric bone density. Limited evidence from one study raises concerns about the use of calcium supplements in children on habitually low calcium intakes as the previously supplemented group went through puberty earlier and had a final height several centimetres shorter than the controls.

Dietary Intake of Schoolchildren and Adolescents in Developing Countries

Author(s): S. Ochola, P.Masibo

School age and adolescence is a dynamic period of growth and development forming a strong foundation for good health and productive adult life. Appropriate dietary intake is critical for forming good eating habits and provides the much needed nutrients for growth, long-term health, cognition and educational achievements. A large proportion of the population globally is in the school age or adolescence, with more than three quarters of these groups living in developingcountries. An up-to-date review and discussion of the dietary intake of schoolchildren and adolescents in developing countries is suitable to provide recent data on patterns of dietary intake, adequacy of nutrient intake and their implications for public health and nutrition issues of concern.This review is based on literature published from 2000 to 2014 on dietary intake of schoolchildren and adolescents aged 6–19 years. A total of 50 studies from 42 countries reporting on dietary intake of schoolchildren and adolescents were included. The dietary intake of schoolchildren and adolescents in developing countries is limited in diversity, mainly comprising plant-based food sources, but with limited intake of fruits and vegetables. There is a low energy intake and insufficient micronutrient intake. At the same time, the available data indicate an emerging trend of consumption of high-energy snacks and beverages, particularly in urban areas.The existence of a negative and positive energy balance in the same population points to the dual burden of malnutrition and highlights the emerging nutrition transition in developing countries. This observation is important for planning public health nutrition approaches that address the concerns of the two ends of the nutrition divide.

Mycotoxin Exposure and Infant and Young Child Growth in Africa What Do We Know

Author(s): M. Lombard

Infant and young child (IYC) growth impairment remains a public health problem in Africa partly because infants are exposed to staple foods (contaminated with mycotoxins) at an early age. Understanding the role of mycotoxins in IYC growth is vital, and this paper systematicallyreviews the available knowledge. Methods: Studies were searched and included if they provided information on African IYC mycotoxin exposure rates and/or growth. Studies were excluded if subjects were older than 15 years, if they were animal studies or focusing on other mycotoxins. Relevant search words were included in search strings. Eight reviews were identified and reference lists scrutinised for additional studies. Results: Ten studies were included; 8 focused on aflatoxin (AF), 2 on fumonisin (FB) and none on deoxynivalenol (DON) and zearalenone (ZEA). AF exposure prevalence reached 100% with levels at 40.4 pg/mg. AF was present in umbilical cords indicating that AF crosses the placenta. Maternal exposure levels were correlated with breast milk levels. The highest levels of serum AF (mean 32.8 pg/mg) were measured in Benin and Togo with 5.4% reaching levels higher than 200 pg/mg. At the end of weaning, children had similar prevalence and exposure levels as adults.Results also indicated that infants with higher levels of maternal exposure had significantly lower height-for-age zscores (HAZ scores), although there was no significant association between cord AF and infant HAZ scores or AF in cord blood and HAZ scores. Significantly higher mean maternalAF levels related to lower weight-for-age z-scores (WAZ scores) were reported, and infants with higher levels of maternal exposure had significantly lower WAZ scores that de-creased over age. Cord AF levels had no effect on infant WAZ scores. One study investigated the association between FB and IYC growth and found that those with FB intakes greater than the provisional maximum tolerable daily intake were significantly shorter (1.3 cm) and lighter (328 g). No studies investigated the role of DON and ZEA. Conclusion: A limited number of epidemiological studies have been conducted,and available research indicates extreme exposures to AF.There are strong associations between AF exposure and stunting and wasting. However, more epidemiological research is urgently needed to understand the role of FB, DON and ZEA in IYC growth.