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The Obesity Epidemic

Obesity is a chronic and often progressive disease that can threaten a person's health.

Obesity is a chronic and often progressive disease, characterised by excess body fat that can threaten or affect a person’s health. It has reached epidemic proportions globally and is one of the biggest health challenges for children in the 21st century.

What does it mean to be overweight or obese?

According to the World Health Organization (2016) a person is overweight or obese if they have abnormal or excessive body fat accumulation that could impair their health.

The difference between being obese and overweight in adulthood is determined by a person’s Body Mass Index (BMI) which provides a measurement of a person’s weight with consideration of their height. A person’s BMI can be calculated by dividing a person’s weight (in kilograms) by the square of their height (in meters) (kg/m2)

If an adult has a BMI of 30 or higher they are considered to be obese, whereas if their BMI is greater than or equal to 25 they are classified as overweight.

Example one:

An adult who is 165cm tall, weighing 85kg would have a BMI of 31, placing them in the obese category.

85 ÷ (1.65 x 1.65) = 31

Example two:

An adult who is 165cm tall, weighing 65kg would have a BMI of 24, placing them in the healthy weight range.

65 ÷ (1.65 x 1.65) = 24

Measurements for Children

The World Health Organization, the International Obesity Taskforce and many other national agencies have developed sex- and age-specific BMI cut-off values for children and adolescents.

A child’s weight status should be determined using an age- and sex-specific percentile for BMI rather than the BMI categories used for adults. This is because children’s body composition varies as they age and varies between boys and girls. Therefore, BMI levels among children and teens need to be expressed relative to other children of the same age and sex.

For children under 5 years of age, The World Health Organization recommends that a child should be considered:

  • Overweight if his/her weight-for-height is greater than 2 standard deviations above WHO Child Growth Standards median; and
  • Obese if his/her weight-for-height is greater than 3 standard deviations above the WHO Child Growth Standards median.

Is it possible to be overweight/obese and still be malnourished?

Yes. Trends show that people in developing countries have gone from being underweight and malnourished to overweight/obese and malnourished.

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Preventing Childhood Obesity: an Early Start to Healthy Living

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FutureLearn - Learning For Life

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