Decade of action on nutrition: our window to act on the double burden of malnutrition

Demaio AR, Branca F. BMJ Glob Health 2017;3:e000492. doi:10.1136/bmjgh-2017-000492 The past half-century has seen a significant shift in the quality and quantity of human diets, and resulting epidemiology, worldwide. 1 2 Nutrition and associated health and demographic transitions were once accepted as near-linear, gradual processes. Heavily influenced by rapid economic and income growth, globalisation, demographic changes and urbanisation, many nations are now experiencing a fast evolving and more complex nutrition reality. In 2014, approximately 1.9 billion adults were estimated to be overweight or obese, while 462 million were underweight. An estimated 41 million children under the age of five were overweight or obese but 155 million were affected by stunting and 52 million by wasting by 2016. In low-income and middle-income countries, almost 5 million children continued to die of undernutrition-related causes; yet, simultaneously many of these same populations now witness an unprecedented rise in childhood overweight and obesity. The result is a double burden of malnutrition—the coexistence of undernutrition along with overweight and obesity or with nutrition-related noncommunicable disease. At the individual level, the double burden of malnutrition may manifest in two or more forms of simultaneous malnutrition—for example, obesity with nutritional anaemia or any vitamin or mineral deficiency or insufficiency. 8 It can also occur across the life course and be temporally separated due to an evolving nutrition environment—for example, overweight in an adult who was previously stunted from childhood undernutrition or from intrauterine growth retardation. At the household level, a situation may arise with contrasting forms of malnutrition in multiple family members—for example, overweight in a mother with stunting in a child or nutritional anaemia in a mother with a grandparent who is overweight or type 2 diabetic. Finally, at the population level, when both undernutrition and overweight are prevalent in the same community, nation or region. The major drivers of this double burden are varied and often insidious, including biological, environmental and behavioural determinants. It is increasingly understood, for example, that undernutrition early in life, and even in one’s mother, may predispose to overweight later in life; that rapid weight gain in childhood can predispose to overweight and obesity in adulthood; that influences known as the social determinants of health have a heavy impact on the nutrition opportunities and resulting status of individuals and populations; and that the globalisation of unhealthy behaviours, driven by rapidly expanding international trade, has led to the commodification and homogenisation of diets—often higher in processed foods and saturated fats, salt and sugar, and lower in vitamins and minerals, than the traditional diets they replace. Decade of action on nutrition: our window to act on the double burden of malnutrition