Obesity and overweight

Key facts

• In 2022, 1 in 8 people in the world were living with obesity. 
• Worldwide adult obesity has more than doubled since 1990, and adolescent obesity has quadrupled.
• In 2022, 2.5 billion adults (18 years and older) were overweight. Of these, 890 million were living with obesity.
• In 2022, 43% of adults aged 18 years and over were overweight and 16% were living with obesity.
• In 2022, 37 million children under the age of 5 were overweight.
• Over 390 million children and adolescents aged 5–19 years were overweight in 2022, including 160 million who were living with obesity.

Overview

Overweight is a condition of excessive fat deposits.

Obesity is a chronic complex disease defined by excessive fat deposits that can impair health. Obesity can lead to increased risk of type 2 diabetes and heart disease, it can affect bone health and reproduction, it increases the risk of certain cancers. Obesity influences the quality of living, such as sleeping or moving.

The diagnosis of overweight and obesity is made by measuring people’s weight and height and by calculating the body mass index (BMI): weight (kg)/height² (m²). The body mass index is a surrogate marker of fatness and additional measurements, such as the waist circumference, can help the diagnosis of obesity.

The BMI categories for defining obesity vary by age and gender in infants, children and adolescents.

Adults

For adults, WHO defines overweight and obesity as follows:

• overweight is a BMI greater than or equal to 25; and
• obesity is a BMI greater than or equal to 30.

For children, age needs to be considered when defining overweight and obesity.

Children under 5 years of age

For children under 5 years of age:

• overweight is weight-for-height greater than 2 standard deviations above WHO Child Growth Standards median; and
• obesity is weight-for-height greater than 3 standard deviations above the WHO Child Growth Standards median.

Children aged between 5–19 years

Overweight and obesity are defined as follows for children aged between 5–19 years:

• overweight is BMI-for-age greater than 1 standard deviation above the WHO Growth Reference median; and
• obesity is greater than 2 standard deviations above the WHO Growth Reference median.

https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight