The World Health Organization (WHO) has updated its fact sheet on Obesity and Overweight ahead of World Obesity Day on 4 March 2024.

Background Information:

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 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.

Key Messages:

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. While just 2% of children and adolescents aged 5–19 were obese in 1990 (31 million young people), by 2022, 8% of children and adolescents were living with obesity (160 million young people).

In 2022, 2.5 billion adults (18 years and older) were overweight. Of these, 890 million were living with obesity. This corresponds to 43% of adults aged 18 years and over (43% of men and 44% of women) who were overweight; an increase from 1990, when 25% of adults aged 18 years and over were overweight. Prevalence of overweight varied by region, from 31% in the WHO South-East Asia Region and the African Region to 67% in the Region of the Americas.

In 2022, 16% of adults aged 18 years and older worldwide were living with obesity.

In 2022, 37 million children under the age of 5 were overweight. Once considered a high-income country problem, overweight is on the rise in low- and middle-income countries. In Africa, the number of overweight children under 5 years has increased by nearly 23% since 2000. Almost half of the children under 5 years who were overweight or living with obesity in 2022 lived in Asia.

Over 390 million children and adolescents aged 5–19 years were overweight in 2022, including 160 million who were living with obesity. The prevalence of overweight (including obesity) among children and adolescents aged 5–19 has risen dramatically from just 8% in 1990 to 20% in 2022. The rise has occurred similarly among both boys and girls: in 2022 19% of girls and 21% of boys were overweight.

In most cases obesity is a multifactorial disease due to obesogenic environments, psycho-social factors and genetic variants. In a subgroup of patients, single major etiological factors can be identified (medications, diseases, immobilization, iatrogenic procedures, monogenic disease/genetic syndrome).

In 2019, higher-than-optimal BMI caused an estimated 5 million deaths from noncommunicable diseases (NCDs) such as cardiovascular diseases, diabetes, cancers, neurological disorders, chronic respiratory diseases, and digestive disorders.

Being overweight in childhood and adolescence affects children’s and adolescents’ immediate health and is associated with greater risk and earlier onset of various NCDs, such as type 2 diabetes and cardiovascular disease.

If nothing is done, the global costs of overweight and obesity are predicted to reach US$ 3 trillion per year by 2030 and more than US$ 18 trillion by 2060.

Children in low- and middle-income countries are more vulnerable to inadequate pre-natal, infant, and young child nutrition. At the same time, these children are exposed to high-fat, high-sugar, high-salt, energy-dense, and micronutrient-poor foods, which tend to be lower in cost but also lower in nutrient quality. These dietary patterns, in conjunction with lower levels of physical activity, result in sharp increases in childhood obesity while undernutrition issues remain unsolved.

It is common to find undernutrition and obesity co-existing within the same country, the same community and the same household.

At the individual level, people may be able to reduce their risk by adopting preventive interventions that include:

• ensure appropriate weight gain during pregnancy;
• practice exclusive breastfeeding in the first 6 months after birth and continued breastfeeding until 24 months or beyond;
• support behaviours of children around healthy eating, physical activity, sedentary behaviours and sleep, regardless of current weight status;
• limit screen time;
• limit consumption of sugar sweetened beverages and energy-dense foods and promote other healthy eating behaviours;
• enjoy a healthy life (healthy diet, physical activity, sleep duration and quality, avoid tobacco and alcohol, emotional self-regulation);
• limit energy intake from total fats and sugars and increase consumption of fruit and vegetables, as well as legumes, whole grains and nuts; and
• engage in regular physical activity.

Useful Links:

Link to the related WHO news release:

https://www.who.int/news/item/01-03-2024-one-in-eight-people-are-now-living-with-obesity

Link to the updated WHO fact sheet:

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

Link to WHO fact sheet on malnutrition:

https://www.who.int/news-room/fact-sheets/detail/malnutrition