On a global scale, there are more people who are obese than underweight. This finding occurs in every region worldwide with the exception of parts of sub-Saharan Africa and Asia. Previously, obesity and overweight were considered problems nearly exclusive to high-income countries; however, the prevalence of these health problems is now rising in low- and middle- income countries. Moreover, obesity and overweight are health issues which are more prevalent in urban areas compared to rural areas. Since 1975, obesity rates have tripled worldwide. As of 2016, 1.9 billion adults (aged 18 years or older) were classified as being overweight, and within these adults, 650 million were classified as obese. This translates to 39% of adults (39% of men and 40% of women) being overweight and 13% of the adult population worldwide (11% of men and 15% of women) being obese in 2016. An estimated 38.2 million under 5 years of age were either overweight or obese as of 2019. In Africa, the number of overweight children under 5 years of age has increased by 24% percent since 2000. Almost half of the children under 5 who were overweight or obese in 2019 lived in Asia. In 2016, over 340 million children and adolescents from ages 5–19 were overweight or obese. 124 million children and adolescents aged 5–19 (6% of girls and 8% of boys) were obese in 2016, as compared to 1975 where obesity affected just under 1% of children and adolescents in this age range. The prevalence of obesity and overweight amongst children and adolescents in this age group has significantly risen from 4% in 1975 to just above 18% in 2016. This marked increase in the rate among children has occurred similarly in both boys and girls, reflected in the 2016 statistic where 18% of girls and 19% of boys were overweight. 24.5% of reproductive age women (age 20–44 years) are estimated to be overweight and 23.0% of reproductive age women are estimated to be obese. It has also been shown that the risk of infertility amongst obese women due to disrupted ovulation is 2.7%. For adult women who are obese and are reproductively active, each unit increase in BMI over a BMI of 32 kg/m2 is associated with a reduction of spontaneous conception rate by 5%. Obesity and overweight among women of reproductive age have been associated with reduced success of conception and a higher risk of complications during pregnancy. Individuals who are obese are at an increased risk of death compared to individuals who are classified as normal weight. This increased risk persists for those who are classified as class 2 and 3 obese.
Obesity and fertility
Age and female fertility
Diet and cancer
Obesity and the environment
Diet and obesity
Obesity and cancer
Abortion and mental health
Alcohol and pregnancy