What is obesity?
Obese is a medical term used to describe a person with a high excess of body fat.
A person is obese if their body mass index (BMI) is greater than 30 kg/m².
An obese person is at greater risk of type-2 diabetes, heart disease and some types of cancer.
What is obesity?
A person is said to be obese if they have such a high excess of body fat that their health might be affected.
Health workers use body mass index (BMI) to assess obesity. They measure the height and mass of a person and then use the equation below to calculate their BMI:
BMI = mass (kg) ÷ height² (m²)
For example, if a person has a mass of 60 kg and a height of 1.65 m:
BMI = 60 kg ÷ 1.65²
BMI = 22 kg/m²
A person is overweight if their BMI is between 25 kg/m² and 30 kg/m². A person with a BMI over 30 kg/m² is said to be obese.
Therefore, the person in our example is not overweight or obese.
How does a person become obese?
A person becomes obese by eating food that supplies more energy than they need.
A 13-year old girl needs about 9,000 kilojoules (KJ) of energy each day. Boys the same age needs around 10,000 KJ/day. Adult women need roughly 8,400 KJ/day and adult men need roughly 10,500 KJ/day. If people consistently eat food that supplies more energy than this, without taking extra exercise, they might eventually become obese.
Health problems related to obesity
Obesity increases the risk of life-threatening health problems, including:
- Heart disease
- Type-2 diabetes
- Some types of cancer, including cancers of the breast, bowel and liver
A person can prevent obesity by eating sensible amounts of nutritious food and exercising regularly. Most obese people can lose weight by eating less and exercising more.
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