Obesity

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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.

BMI = kg/m2 where kg is a person's weight in kilograms and m2 is their height in metres squared.

Healthy range of BMI is 18.5 to 24.9. Diabetes Details Image

For ADULTS, WHO defines overweight and obesity as follows :-

  • Overweight is a BMI greater than or equal to 25
  • Obesity is a BMI greater than or equal to 30
For 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
  • Obesity is greater than 2 standard deviations above the WHO Growth Reference median

For CHILDREN under 5 years of age :-

  • Overweight is weight-for-height greater than 2 standard deviations above WHO Child Growth Standards median
  • Obesity is weight-for-height greater than 3 standard deviations above the WHO Child Growth Standards median
CAUSES

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
  • An increase in physical inactivity due to the increasingly sedentary nature of many forms of work, changing modes of transportation, and increasing urbanization

Raised BMI is a major risk factor for noncommunicable diseases such as :-

  • Cardiovascular diseases (mainly heart disease and stroke)
  • Diabetes
  • Musculoskeletal disorders (especially osteoarthritis – a highly disabling degenerative disease of the joints)
  • Some cancers (including endometrial, breast, ovarian, prostate, liver, gallbladder, kidney, and colon)
The risk for these noncommunicable diseases increases, with increases in BMI.

Childhood obesity is associated with a higher chance of obesity, premature death and disability in adulthood. But in addition to increased future risks, obese children experience breathing difficulties, increased risk of fractures, hypertension, early markers of cardiovascular disease, insulin resistance and psychological effects.