Overweight is a condition of excessive fat deposits. Obesity is a chronic, complex disease characterized by excessive fat deposits that can impair health. Obesity can lead to an increased risk of type 2 diabetes and heart disease, it can affect bone health and reproductive function, and it increases the risk of certain cancers. Obesity affects quality of life, such as sleep or mobility.

Overweight and obesity are diagnosed by measuring a person's weight and height and calculating the body mass index (BMI): weight (kg)/height² (m²). BMI is a surrogate marker of obesity, and additional measurements such as waist circumference can help in the diagnosis of obesity.

BMI categories for 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;

obesity is a BMI greater than or equal to 30.

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

For children under 5 years of age:

Overweight is a body weight to height ratio that exceeds the median of the WHO child height standards by more than 2 standard deviations;

obesity is a body weight/height ratio that exceeds the median of the WHO child growth standards by more than 3 standard deviations.

Graphs and tables: WHO child growth standards for children under 5 years of age.

Children aged 5 to 19 years

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

overweight is a BMI by age that exceeds the WHO median for height by more than 1 standard deviation;

obesity is more than 2 standard deviations above the WHO median for growth rate.

Charts and tables: WHO growth recommendations for children aged 5 to 19 years.

Facts about overweight and obesity

In 2024, 2.5 billion adults aged 18 years and older were overweight, including more than 890 million obese adults. This equates to 43% of adults aged 18 years and older (43% of men and 44% of women) being overweight; an increase from 1990, when 25% of adults aged 18 years and older were overweight. The prevalence of overweight varied by region, ranging from 31% in the WHO South-East Asia and Africa Region to 67% in the Americas Region.

In 2024, about 16% of adults aged 18 years and older worldwide were obese. The prevalence of obesity more than doubled globally between 1990 and 2024.

In 2024, an estimated 37 million children under the age of 5 are overweight. Overweight was once considered a problem in high-income countries, but it is now on the rise in low- and middle-income countries. In Africa, the number of overweight children under 5 has increased by nearly 23% since 2000. Nearly half of the children under 5 who are overweight or obese in 2024 live in Asia.

More than 390 million children and adolescents aged 5-19 years were overweight in 2024. The prevalence of overweight (including obesity) among children and adolescents aged 5-19 years increased dramatically from 8% in 1990 to 20% in 2024. This increase was observed equally among boys and girls: in 2024, 19% of girls and 21% of boys were overweight.

While in 1990 only 2% of children and adolescents aged 5-19 were obese (31 million young people), by 2024 8% of children and adolescents are obese (160 million young people).

Juraeva Saodat Dadajonovna- c.m.s., associate professor at the department of endocrinology, Avicenna Tajik State Medical University

Translated Ismoilov R.