Nutrition in pregnancy and early childhood and associations with obesity in developing countries.

Concerns about the increasing rates of obesity in developing countries have led many policy makers to question the impacts of maternal and early child nutrition on risk of later obesity. The purposes of the review are to summarise the studies on the associations between nutrition during pregnancy and infant feeding practices with later obesity from childhood through adulthood and to identify potential ways for preventing obesity in developing countries. As few studies were identified in developing countries, key studies in developed countries were included in the review. Poor prenatal dietary intakes of energy, protein and micronutrients were shown to be associated with increased risk of adult obesity in offspring. Female offspring seem to be more vulnerable than male offspring when their mothers receive insufficient energy during pregnancy. By influencing birthweight, optimal prenatal nutrition might reduce the risk of obesity in adults. While normal birthweights (2500-3999 g) were associated with higher body mass index (BMI) as adults, they generally were associated with higher fat-free mass and lower fat mass compared with low birthweights (<2500 g). Low birthweight was associated with higher risk of metabolic syndrome and central obesity in adults. Breastfeeding and timely introduction of complementary foods were shown to protect against obesity later in life in observational studies. High-protein intake during early childhood however was associated with higher body fat mass and obesity in adulthood. In developed countries, increased weight gain during the first 2 years of life was associated with a higher BMI in adulthood. However, recent studies in developing countries showed that higher BMI was more related to greater lean body mass than fat mass. It appears that increased length at 2 years of age was positively associated with height, weight and fat-free mass, and was only weakly associated with fat mass. The protective associations between breastfeeding and obesity may differ in developing countries compared to developed countries because many studies in developed countries used formula feeding as a control. Future research on the relationship between breastfeeding, timely introduction of complementary feeding or rapid weight gain and obesity are warranted in developing countries. The focus of interventions to reduce risk of obesity in later life in developing countries could include: improving maternal nutritional status during pregnancy to reduce low birthweight; enhancing breastfeeding (including durations of exclusive and total breastfeeding); timely introduction of high-quality complementary foods (containing micronutrients and essential fats) but not excessive in protein; further evidence is needed to understand the extent of weight gain and length gain during early childhood are related to body composition in later life.