Obesity

Overweight and obesity are defined as "abnormal or excessive fat accumulation that may impair health"

Body mass index (BMI) – the weight in kilograms divided by the square of the height in meters (kg/m2) – is a commonly used index to classify overweight and obesity in adults. WHO defines overweight as a BMI equal to or more than 25, and obesity as a BMI equal to or more than 30.

More than 1.9 billion adults were overweight in 2016, and 650 million obese

In 2016, more than 1.9 billion adults were overweight and 650 million were obese. At least 2.8 million people each year die as a result of being overweight or obese. The prevalence of obesity nearly tripled between 1975 and 2016. Once associated with high-income countries, obesity is now also prevalent in low- and middle-income countries.

39 million children under the age of 5 were overweight or obese in 2020.

Childhood obesity is one of the most serious public health challenges of the 21st century. Overweight children are likely to become obese adults. They are more likely than non-overweight children to develop diabetes and cardiovascular diseases at a younger age, which in turn are associated with a higher chance of premature death and disability.

Overweight and obesity are linked to more deaths worldwide than underweight

Most of the world's population live in a country where there are more people overweight and obese than underweight. This includes all high-income and middle-income countries. Diabetes, ischaemic heart disease and certain cancers are attributable to overweight and obesity.

For an individual, obesity is usually the result of an imbalance between calories consumed and calories expended

An increased consumption of energy dense foods, without an equal increase in physical activity, leads to an unhealthy increase in weight. Decreased levels of physical activity will also result in an energy imbalance and lead to weight gain.

Children's diet and physical activity habits are influenced by their surrounding environment

Social and economic development as well as policies in the areas of agriculture, transport, urban planning, environment, education, food processing, distribution and marketing influence children's dietary habits and preferences as well as their physical activity patterns. Increasingly, these influences are promoting unhealthy weight gain leading to a steady rise in the prevalence of childhood obesity.

Eating a healthy diet can help prevent obesity

People can:

1. maintain a healthy weight
2. limit total fat intake and shift fat consumption away from saturated fats to unsaturated fats
3. increase consumption of fruit, vegetables, pulses, whole grains and nuts
4. limit the intake of free sugars and salt.

Regular physical activity helps maintain a healthy body

People should engage in adequate levels of physical activity throughout their lives. At least 150 minutes of regular, moderate-intensity physical activity per week reduces the risk of cardiovascular disease, diabetes, colon cancer and breast cancer. Muscle strengthening and balance training can reduce falls and improve mobility among older adults. More activity may be required for weight control.

Curbing the global obesity epidemic requires a population-based multisectoral, multi-disciplinary, and culturally relevant approach

WHO's Action Plan for the Global Strategy for the Prevention and Control of Noncommunicable Diseases provides a roadmap to establish and strengthen initiatives for the surveillance, prevention and management of noncommunicable diseases, including obesity.