Obesity and Weight Management
                     OBESITY AND WEIGHT 
MANAGEMENT
What is obesity?
• Overweight and obesity are defined as abnormal or excessive fat accumulation that may impair health. 
• Body mass index (BMI) is a simple index of weight-for-height that is commonly used to classify overweight 
and obesity in adults. It is defined as a person's weight in kilograms divided by the square of his height in 
meters (kg/m2).
Source: www.who.int
Key facts
• Worldwide obesity has nearly tripled since 1975.
• In 2016, more than 1.9 billion adults, 18 years and older, were overweight. Of these over 650 million were 
obese.
Source: www.who.int
Key facts Cont.
• 39% of adults aged 18 years and over were overweight in 2016, and 13% were obese.
• Most of the world's population live in countries where overweight and obesity kills more people than 
underweight.
Source: www.who.int
Key facts Cont.
• 39 million children under the age of 5 were overweight or obese in 2020.
• Over 340 million children and adolescents aged 5-19 were overweight or obese in 2016.
Source: www.who.int
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.
Source: www.who.int
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.
Source: www.who.int
What causes obesity?
The fundamental cause of obesity and overweight is an energy imbalance between calories consumed and 
calories expended. Globally, there has been:
•an increased intake of energy-dense foods that are high in fat and sugars; and
•an increase in physical inactivity due to the increasingly sedentary nature of many forms of work, changing 
modes of transportation, and increasing urbanization.
Source: www.who.int
Common health consequences 
Raised BMI is a major risk factor for noncommunicable diseases such as:
•cardiovascular diseases (mainly heart disease and stroke), which were the leading cause of death in 2012
•diabetes
•musculoskeletal disorders (especially osteoarthritis – a highly disabling degenerative disease of the joints)
•some cancers (including endometrial, breast, ovarian, prostate, liver, gallbladder, kidney)
Source: www.who.int
Burden of malnutrition
Many low- and middle-income countries are now facing a "double burden" of malnutrition.
•While these countries continue to deal with the problems of infectious diseases and undernutrition, they are 
also experiencing a rapid upsurge in noncommunicable disease risk factors such as obesity and overweight, 
particularly in urban settings.
Source: www.who.int
How can obesity be reduced?
At the individual level, people can:
•limit energy intake from total fats and sugars;
•increase consumption of fruit and vegetables, as well as legumes, whole grains and nuts; and
•engage in regular physical activity (60 minutes a day for children and 150 minutes spread through the week 
for adults).
Source: www.who.int