The epidemiological burden of obesity in childhood: a worldwide epidemic requiring urgent action

Abstract

Background: In recent decades, the prevalence of obesity in children has increased dramatically. This worldwide epidemic has important consequences, including psychiatric, psychological and psychosocial disorders in childhood and increased risk of developing non-communicable diseases (NCDs) later in life. Treatment of obesity is difficult and children with excess weight are likely to become adults with obesity. These trends have led member states of the World Health Organization (WHO) to endorse a target of no increase in obesity in childhood by 2025.

Main body: Estimates of overweight in children aged under 5 years are available jointly from the United Nations Children's Fund (UNICEF), WHO and the World Bank. The Institute for Health Metrics and Evaluation (IHME) has published country-level estimates of obesity in children aged 2-4 years. For children aged 5-19 years, obesity estimates are available from the NCD Risk Factor Collaboration. The global prevalence of overweight in children aged 5 years or under has increased modestly, but with heterogeneous trends in low and middle-income regions, while the prevalence of obesity in children aged 2-4 years has increased moderately. In 1975, obesity in children aged 5-19 years was relatively rare, but was much more common in 2016.

Conclusions: It is recognised that the key drivers of this epidemic form an obesogenic environment, which includes changing food systems and reduced physical activity. Although cost-effective interventions such as WHO 'best buys' have been identified, political will and implementation have so far been limited. There is therefore a need to implement effective programmes and policies in multiple sectors to address overnutrition, undernutrition, mobility and physical activity. To be successful, the obesity epidemic must be a political priority, with these issues addressed both locally and globally. Work by governments, civil society, private corporations and other key stakeholders must be coordinated.

Keywords: Adolescents; Children; Global health; Obesity; Overweight.

Fig. 1

Obesity prevalence for girls and boys aged 2–4 years in 1980, by country. Estimates of obesity prevalence in (a) girls and (b) boys aged 2–4 years were published by the Institute for Health Metrics and Evaluation using the International Obesity Taskforce growth reference [46] (see Table 1)

Fig. 2

Obesity prevalence for girls and boys aged 2–4 years in 2015, by country. Estimates of obesity prevalence in (a) girls and (b) boys aged 2–4 years were published by the Institute for Health Metrics and Evaluation using the International Obesity Taskforce growth reference [46] (see Table 1)

Fig. 3

Division of the number of girls and boys aged 2–4 years with obesity in 1980, by country. Estimates of obesity in (a) girls and (b) boys were published by the Institute for Health Metrics using the International Obesity Taskforce growth reference [46] (see Table 1)

Fig. 4

Division of the number of girls and boys aged 2–4 years with obesity in 2015, by country. Estimates of obesity in (a) girls and (b) boys were published by the Institute for Health Metrics using the International Obesity Taskforce growth reference [46] (see Table 1)

Fig. 5

Obesity prevalence for girls and boys aged 5–19 years in 1975, by country. Estimates of obesity in (a) girls and (b) boys were published by the Non-Communicable Diseases Risk Factor Collaboration (NCD-RisC) using the World Health Organization growth reference [47] (see Table 1)

Fig. 6

Obesity prevalence for girls and boys aged 5–19 years in 2016, by country. Estimates of obesity in (a) girls and (b) boys were published by the Non-Communicable Diseases Risk Factor Collaboration (NCD-RisC) using the World Health Organization growth reference [47] (see Table 1)

Fig. 7

Proportional increase in obesity for girls and boys aged 5–19 years, between 1975 and 2016. Estimates of obesity for (A) girls and (B) boys were published by the Non-Communicable Diseases Risk Factor Collaboration (NCD-RisC) using the World Health Organization growth reference [47] (see Table 1)

Fig. 8

Division of the number of girls and boys aged 5–19 years with obesity in 1975, by country. Estimates of obesity for (a) girls and (b) boys were published by the Non-Communicable Diseases Risk Factor Collaboration (NCD-RisC) using the World Health Organization growth reference [47] (see Table 1)

Fig. 9

Division of the number of girls and boys aged 5–19 years with obesity in 2016, by country. Estimates of obesity for (a) girls and (b) boys were published by the Non-Communicable Diseases Risk Factor Collaboration (NCD-RisC) using the World Health Organization growth reference [47] (see Table 1)

Fig. 10

Comparison of obesity prevalence in girls and boys aged 5–19 years in 1975 and 2016. Estimates of obesity in (a) 1975 and (b) 2016 were published by the Non-Communicable Diseases Risk Factor Collaboration (NCD-RisC) using the World Health Organization growth reference [47] (see Table 1)

Fig. 11

Comparison of the number of girls and boys aged 5–19 years with obesity in 1975 and 2016. Estimates of obesity for (a) 1975 and (b) 2016 were published by the Non-Communicable Diseases Risk Factor Collaboration (NCD-RisC) using the World Health Organization growth reference [47] (see Table 1)