What is overweight and obesity?
Overweight and obesity are the result of abnormal or excessive body fat that can be harmful to your health.
Body Mass Index (BMI) is a simple ratio of body weight to height, often used to diagnose obesity and overweight in adults. The index is calculated as the ratio of body weight in kilograms to the square of growth in meters (kg / m2).
According to the WHO, the diagnosis of “overweight” or “obesity” in adults is made in the following cases:
BMI greater than or equal to 25 – overweight;
A BMI greater than or equal to 30 is obesity.
BMI is the most convenient measure for assessing the level of obesity and overweight in a population, since it is the same for both sexes and for all age categories of adults. However, BMI should be considered an approximate criterion, as in different people it can correspond to a different degree of completeness.
In children, when determining excess weight and obesity, age should be considered.
Children under 5 years old
In children under the age of 5 years, overweight and obesity are defined as follows:
overweight – if the ratio “body weight / height” exceeds the median value specified in the Standard indicators of physical development of children (WHO), more than two standard deviations;
obesity – if the ratio “body weight / height” exceeds the median value indicated in the Standard indicators of physical development of children (WHO), more than three standard deviations;
Charts and tables: WHO standard indicators for the physical development of children under 5 years old – in English
Children aged 5 to 19 years
In children aged 5 to 19 years, overweight and obesity are defined as follows:
overweight – if the ratio of “BMI / age” exceeds the median value specified in the Standard indicators of physical development of children (WHO), more than one standard deviation;
obesity – if the ratio of “BMI / age” exceeds the median value specified in the Standard indicators of physical development of children (WHO), more than two standard deviations;
Charts and tables: WHO standard indicators for the physical development of children and adolescents aged 5-19 years – in English
Facts About Overweight and Obesity
The following are some recent global estimates by WHO:
In 2016, more than 1.9 billion adults over 18 were overweight. Of these, over 650 million were obese.
According to 2016 data, 39% of adults over 18 years of age (39% of men and 40% of women) were overweight.
In 2016, about 13% of the world’s adult population (11% of men and 15% of women) were obese.
Between 1975 and 2016, the number of obese people worldwide more than tripled.
In 2016, an estimated 41 million children under 5 years old were overweight or obese. Overweight and obesity, previously considered characteristic of high-income countries, are now becoming more common in low- and middle-income countries, especially in cities. In Africa, since 2000, the number of obese children under 5 years old has grown by almost 50%. In 2016, nearly half of overweight or obese children under 5 lived in Asia.
In 2016, 340 million children and adolescents aged 5 to 19 years were overweight or obese.
The prevalence of overweight and obesity among children and adolescents aged 5 to 19 years has risen sharply from just 4% in 1975 to a little over 18% in 2016. This growth is equally distributed among children and adolescents of both sexes: in 2016, 18% of girls and 19% of boys were overweight.
In 1975, slightly less than 1% of children and adolescents aged 5 to 19 years were obese, and in 2016 their number reached 124 million (6% of girls and 8% of boys).
In general, more people die from the effects of overweight and obesity in the world than from the effects of abnormally low body weight. The number of obese people exceeds the number of people with reduced body weight; this is the case in all regions except for parts of sub-Saharan Africa and Asia.
What causes overweight and obesity?
The main cause of obesity and overweight is an energy imbalance in which the calorie content of the diet exceeds the energy needs of the body. The following trends are observed worldwide:
increased consumption of foods with high energy density and high fat content;
decreased physical activity due to the increasingly sedentary nature of many activities, changes in transportation methods and increasing urbanization.
Changes in diet and physical activity are often the result of environmental and social changes as a result of a development process that is not accompanied by appropriate incentive policies in sectors such as health, agriculture, transport, urban planning, environmental protection.
Author Name : M.Zia Nadeem Jhullan