Global Trends in Obesity

This chapter describes the current prevalence and time trends of obesity in adults and children worldwide. The obesity epidemic has become a major public health problem in many countries, and the problem continues to grow. Obesity has many health consequences such as cardiovascular diseases, diabetes, musculoskeletal disorders, and some cancers. Worldwide obesity has nearly tripled since 1975. In 2016, 39% of adults aged 18 years and over were overweight, and 13% were obese. In just 40 years, the number of school-age children and adolescents with obesity has risen more than tenfold, from 11 million to 124 million. Childhood obesity has long-term effects on mortality and morbidity. Overweight and obese children are likely to maintain their status into adulthood and are at higher risks for developing chronic diseases. Moreover, a growing body of literature suggests that the socioeconomic status and obesity association is complex and varies by several demographic or environmental factors. With the progression of the obesity epidemic, it is possible that such associations (e.g., association between socioeconomic status and prevalence of obesity) may become weaker or even disappear in some industrialized countries or change direction in some developing countries in the future. The epidemic calls for timely and effective population-based approaches to prevent the condition. Obesity is largely preventable by having healthy lifestyles that include healthy eating and adequate physical activity. The development of national policies and population-based intervention programs is needed to combat the obesity epidemic and promote public health in many countries.