Epidemiology of Obesity: The Global Situation

Obesity has become a serious public health threat in many industrialized and developing countries worldwide, and the problem continues to grow. Obesity has many health and financial consequences to individuals and society. Different measures have been used to classify overweight and obesity in adults and children, while body mass index (BMI) cut points have been widely used to define overweight and obesity. Different BMI cutoff point are being used over time and across countries at present. It is estimated in 2008 worldwide 35 % of adults aged ≥20 years were overweight and 11 % were obese; more than 1.4 billion adults were overweight. Of these, over 200 million men and nearly 300 million women were obese. It is projected, except for the World Health Organization’s (WHO) African region (lack of data), the overall combined prevalence of overweight and obesity in adults and children is about 20–40 % in the WHO regions. In the United States, based on 2009–2010 national survey data, 66.8 % of adults were overweight or obese (BMI ≥ 30), and 35.9 % were obese (BMI ≥ 25). The prevalence of obesity varied across ethnic groups: ranging from 34.9 % in non-Hispanic whites to 49.6 % in non-Hispanic blacks. In the US children aged 2–19 years old, the combined prevalence is 31.8 % but varies by age and ethnicity. The US children aged 2–5 (26.7 %) and non-Hispanic whites (27.9 %) had the lowest prevalence among the age and ethnic groups, respectively. Overweight and obesity are largely preventable by having healthy lifestyles. The development of population-based intervention programs and related national policies is crucial to combat the obesity epidemic and promote public health globally.