What exactly are obesity and overweight?
Obesity and overweight are defined as abnormal or excessive fat accumulations that can harm one’s health.
Body mass index (BMI) is a simple weight-for-height index that is commonly used to classify adults as overweight or obese. It is calculated by dividing a person’s weight in kilogrammes by the square of his height in metres (kg/m2).
WHO defines overweight and obesity in adults as follows:
Overweight is defined as having a BMI greater than or equal to 25; and
Obesity is defined as a BMI of 30 or higher.
Because it is the same for both sexes and all ages of adults, BMI is the most useful population-level measure of overweight and obesity. It should, however, be regarded as a rough guide because it may not correspond to the same degree of fatness in different individuals.
When defining overweight and obesity in children, age must be taken into account.
CHILDREN UNDER THE AGE OF FIVE
For children under the age of five:
Overweight is defined as having a weight-for-height ratio greater than two standard deviations above the WHO Child Growth Standards median; and
Obesity is defined as having a weight-for-height ratio greater than three standard deviations above the WHO Child Growth Standards median.
CHILDREN AGED 5-19
For children aged 5–19 years, overweight and obesity are defined as follows:
Overweight is defined as having a BMI for age that is more than one standard deviation above the WHO Growth Reference Median; and
Obesity exceeds the WHO Growth Reference Median by more than two standard deviations.
Overweight and obesity facts
Following are some recent WHO global estimates.
In 2016, over 1.9 billion adults aged 18 and up were overweight. Over 650 million of these adults were obese.
In 2016, 39 percent of adults aged 18 and up were overweight (39 percent of men and 40 percent of women).
In 2016, approximately 13% of the world’s adult population (11 percent of men and 15% of women) were obese.
Between 1975 and 2016, the global prevalence of obesity nearly tripled.
An estimated 38.2 million children under the age of five were overweight or obese in 2019.
What factors contribute to obesity and overweight?
Obesity and overweight are caused by an energy imbalance between calories consumed and calories expended. There has been worldwide:
an increase in the consumption of energy-dense foods high in fat and sugar; and
an increase in physical inactivity as a result of the increasingly sedentary nature of many jobs, changing modes of transportation, and increased urbanisation
Environmental and societal changes associated with development, as well as a lack of supportive policies in sectors such as health, agriculture, transportation, urban planning, the environment, food processing, distribution, marketing, and education, frequently cause changes in dietary and physical activity patterns.
What are the most common health consequences of being overweight or obese?
A high BMI is a significant risk factor for noncommunicable diseases such as:
Cardiovascular diseases (most notably heart disease and stroke) were the leading cause of death in 2012.
Musculoskeletal disorders (particularly osteoarthritis, a severely disabling degenerative joint disease);
a few cancers (including endometrial, breast, ovarian, prostate, liver, gallbladder, kidney, and colon).
With increasing BMI, the risk of these noncommunicable diseases rises.
Childhood obesity is linked to an increased risk of adult obesity, premature death, and disability. Obese children, however, have breathing difficulties, an increased risk of fractures, hypertension, early markers of cardiovascular disease, insulin resistance, and psychological effects, in addition to increased future risks.
How can we reduce overweight and obesity?
Obesity and overweight, as well as the diseases associated with them, are largely preventable. Supportive environments and communities play a critical role in shaping people’s choices by making the choice of healthier foods and regular physical activity the easiest (the choice that is most accessible, available, and affordable), thereby preventing overweight and obesity.
Individuals can do the following:
- Reduce your intake of total fats and sugars;
- eat more fruits and vegetables, as well as legumes, whole grains, and nuts; and
- participate in regular physical activity (60 minutes a day for children and 150 minutes spread through the week for adults).
Individual responsibility can only be fully realised when people have access to a healthy way of life. As a result, at the societal level, it is critical to support individuals in adhering to the above recommendations by sustaining the implementation of evidence-based and population-based policies that make regular physical activity and healthier dietary choices available, affordable, and easily accessible to everyone, particularly the poorest individuals. A tax on sugar-sweetened beverages is one example of such a policy.
The food industry can play an important role in promoting healthy diets by doing the following:
- lowering processed food fat, sugar, and salt content;
- ensuring that healthy and nutritious food options are accessible and affordable to all consumers;
- restricting marketing of foods high in sugars, salt and fats, especially those foods aimed at children and teenagers; and
- ensuring the availability of healthy food choices and supporting regular physical activity practice in the workplace.