Weight gain that is abnormal or excessive and poses a risk to health is what is meant by the terms "overweight" and "obesity." Overweight is defined as a body mass index (BMI) of 25, and obesity as a BMI of greater than 30. According to the global burden of illness, the problem has reached epidemic proportions, with over 4 million people dying annually as a result of being overweight or obese in 2017. The prevalence of overweight and obesity in both adults and children is rising. Globally, the prevalence of overweight or obesity among children and adolescents aged 5 to 19 more than quadrupled from 4% to 18% between 1975 and 2016. With the exception of sub-Saharan Africa, more people are obese than underweight today, which is one side of the double burden of malnutrition.