The double burden of malnutrition: aetiological pathways and consequences for health

Abstract

• Malnutrition has long been researched and addressed in two distinct silos, focusing either on chronic 2 or acute undernutrition, energy inadequacy and micronutrient deficiencies, or on overweight, obesity 3 and dietary excess. The contemporary reality of the double burden of malnutrition is different, making it 4 impossible to separate these issues, but also indicating shared opportunities to address them. 5 • Malnutrition harms health throughout the life-course, but its emergence early in life has particularly 6 pernicious consequences. A variety of physiological mechanisms propagate effects of early-life 7 malnutrition across the life-course, while adolescent and adult malnutrition can transmit effects to the 8 next generation. 9 • Different forms of malnutrition can interact through the life-course and across generations. In some 10 settings, early stunting may predispose to a more central distribution of adiposity at later ages, while 11 the extent to which maternal obesity adversely affects early growth and development of the offspring 12 may be exacerbated if the mother herself was under-nourished in early life. 13 • Life-course exposure to the double burden of malnutrition (early undernutrition followed by later 14 overweight) increases the risk of non-communicable disease, by imposing a high metabolic load on a 15 depleted capacity for homeostasis. The health costs of adult obesity are therefore exacerbated among 16 those who previously experienced undernutrition. In women, life-course exposure to the double burden 17 of malnutrition increases the risk of childbirth complications. 18 • Exclusive and appropriate breast-feeding protects infants against all forms of malnutrition, and 19 protects mothers against diabetes and breast cancer, in part through healthy-weight benefits. However, 20 maternal obesity, diabetes and micronutrient deficiencies alter the biology of lactation, and should be 21 addressed to maximise the success of breast-feeding. 22 • Exposure to the double burden of malnutrition can only be fully understood in the context of broader 23 societal drivers acting across culture, behaviour and technology. Various groups are at high risk of the 24 double burden through elevated exposure to these drivers, often exacerbated by biological 25 susceptibility. 26 • Developmental responses to malnutrition in early life are shaped by ecological factors, such as 27 pathogen burden and extrinsic mortality risk. An evolutionary perspective, focusing on how our 28 biological plasticity was shaped in ancestral environments to promote survival and reproduction, may 29 help design interventions that promote linear growth and lean tissue accretion rather than excess 30 adiposity. 31 • Inter-generational cycles of malnutrition have proven difficult to disrupt through public health 32 interventions. Major societal shifts are required regarding nutrition and public health, in order to 33 implement comprehensive change that is sustained over decades, and scaled up into the entire global 34 food system.

Mapping local patterns of childhood overweight and wasting in low- and middle-income countries between 2000 and 2017

“…Overall, food security has improved across LMICs in the past decade, which has led to increased availability of calories at the population level 23 . Although overweight is a reflection of excess calorie intake and reduced energy expenditure, there is a growing recognition that at the root of the rising rates of overweight are complex interactions between societal, environmental, food industry and individual factors, including biological, psychological and economical factors 24 . Understanding the factors underpinning these trends is key to predicting how nutrition programs can accelerate amelioration of wasting without incurring high rates of childhood overweight.…”

“…To better respond to the diverse and rapidly evolving nutrition challenges facing LMICs, sustainable and healthpromoting food systems are needed to slow the development of DBM. Due to the multiple causality of malnutrition, multisector collaboration is required, including agriculture, trade and industry, environment, communication and education, all working towards policy and intervention coherence 8,24 . Quartile cutoffs were 0-5%, ≥5-10%, ≥10-15% and ≥15%.…”

Consensus of the Brazilian Association of Nutrology on Milky Feeding of Children Aged 1–5 Years Old

“…However, as a result of social, economic and demographic changes that have occurred globally in the last 3 decades, the two extremes of malnutrition have been related to common triggers and re-contextualized in a single spectrum. 13 Throughout their lives, a growing proportion of individuals will be exposed to the rapidly expanding obesogenic environment and causes of malnutrition that still persist. Studies with representative samples of the Brazilian population demonstrate the unequal distribution of the magnitude of complications related to nutritional problems in childhood and reveal worrying trends for the future.…”

“…The combination of weight deficit and growth in early stages of life, with subsequent progression to overweight, is an example resulting from the nutritional transition that contributes to the increased risk of developing NCD in adulthood. The consequences that high metabolic burden determines on an organism with impaired homeostasis capacity can be explained by the concept of Metabolic Programming, 13 which conspires with genetic factors for the adjustment that affects the body weight and health of the individual throughout life. 28 Development and growth occur due to a succession of critical periods and great plasticity known as "windows" when the phenotype is particularly sensitive to exposoma stimuli.…”

“…Thus, the incidence of risk factors for changes in nutritional status in early stages of life may change the functioning of the organism permanently. 13 Fisberg et al have evaluated the risk factors that determine the establishment of exogenous obesity in childhood: early weaning, introduction of inappropriate complementary foods, inadequate consumption and preparation of milky formulas, eating behavior disorders and misfits of family relationships. The same study has pointed out other contextual risk factors, such as the difficult access to areas for the practice of physical activities and active leisure in urban cities, the universalization of access to industrialized restaurants and foods, the inadequacies of the school infrastructure and the poor quality of school meals.…”