Childhood and adolescent overweight and obesity in Latin America: a systematic review

Summary

The number of children and adolescents who are overweight or obese worldwide is alarming. We did a systematic review to estimate the prevalence of overweight and obesity in children aged 0–19 years in Latin America. We searched specialised databases and seven books for relevant studies that were done in Spanish-speaking and Portuguese-speaking Latin American and Caribbean countries and published in peer-reviewed journals between January 2008, and April 2013. Indicators used were BMI (kg/m²) in all age groups and weight-for-height in children younger than 5 years. We identified 692 publications and included 42. Estimated prevalence of overweight in children younger than 5 years in Latin America was 7·1% with the weight-for-height WHO 2006 classification method. National combined prevalences of overweight and obesity with the WHO 2007 classification method ranged from 18·9% to 36·9% in school-age children (5–11 years) and from 16·6% to 35·8% in adolescents (12–19 years). We estimated that 3·8 million children younger than 5 years, 22·2–25·9 million school-age children, and 16·5–21·1 million adolescents were overweight or obese. Overall, between 42·5 and 51·8 million children aged 0–19 years were affected—ie, about 20–25% of the population. Although undernutrition and obesity coexist in the region, policies in most countries favour prevention of undernutrition, and only a few countries have implemented national policies to prevent obesity. In view of the number of children who are overweight or obese, the associated detrimental effects on health, and the cost to health-care systems, implementation of programmes to monitor and prevent unhealthy weight gain in children and adolescents are urgently needed throughout Latin America.

Introduction

The prevalence of childhood overweight and obesity has increased worldwide in recent decades.¹ Although prevalence seems to be levelling off in some high-income countries,² it is still increasing rapidly in most Latin American countries.³ Obesity in childhood has immediate consequences on health including hyperlipidaemia, hypertension, and abnormal glucose tolerance. It also increases the risk of orthopaedic, neurological, pulmonary, gastroenterological, endocrine, and hepatic disorders, especially when obesity is severe. Other consequences are psychosocial, including discrimination, negative self-image, social exclusion, and depression. As severe obesity is becoming more common in children and adolescents, so too are these short-term health consequences.4, 5, 6 From one third to one half of obese children become obese adults;⁷ one possible mechanism underyling this observation is that maturation early in life leads to increased adiposity in adulthood.5, 7, 8 Importantly, overweight and obesity are well-recognised risk factors for non-communicable diseases in adults such as hypertension, type 2 diabetes, cardiovascular diseases, gallbladder disease, osteoarthritis, endocrine disorders, some forms of cancer, and sleep apnoea, among others.9, 10, 11 Thus, an increase in the prevalence of childhood overweight and obesity is likely to be followed by increased incidences of chronic diseases, with their associated disabilities and mortality, at younger ages during adulthood; increased expenditures for families and health-care systems are also anticipated.11, 12, 13

In view of the health, social, and economic effects, monitoring the magnitude and distribution of childhood overweight and obesity is crucial for policy making. Data for the prevalence of overweight in children younger than 5 years in Latin America by use of the WHO Global Database on Child Growth and Malnutrition¹⁴ have been published for the period between 1990 and 2011.15, 16, 17 Additionally, a book chapter reported the prevalence of overweight and obesity in children and adolescents in South American countries with data collected until 2010.³ However, to the best of our knowledge, no publications are available in peer-reviewed journals reporting overweight and obesity in children aged 5 years and older and in adolescents throughout Latin America. We aimed to review the present prevalence of overweight and obesity in children younger than 5 years, school-age children (aged 5–11 years), and adolescents (aged 12–19 years) in Latin America, and to discuss programme and policy implications. This information is crucial to position childhood obesity in the political agenda and foster the design and implementation of policies to tackle this epidemic.