Obesity is now well recognised as a serious global health problem. The World Health Organisation (WHO) estimates over 1 billion adults worldwide are overweight or obese and that more than 2 million die each year due to being overweight or obese. Childhood obesity rates are also rising and WHO estimates globally, over 40 million preschool children are overweight.
Definition of Obesity
Obesity and overweight are defined by WHO as “abnormal or excessive fat accumulation that presents a risk to health.” Obesity occurs when calorie consumption exceeds energy expenditure; or when we consume far more calories (food) than we can use (exercise).
Causes of obesity
There is no one single cause for obesity. Obesity often arises as a result of interaction of many factors whether they be medical, physiological, social, psychological, genetic or environmental.
Body Mass Index (BMI)
BMI is a way of measuring or quantifying the degree of obesity taking into account the height of the individual. It is calculated by dividing ones weight (in kg) by ones height (in metres2).
|BMI (kg/m2)||WHO classification||Common Clinical description|
|30-34.9||Obese class 1||Obese|
|35-39.9||Obese class 2||Severe obesity|
|40-49.9||Obese class 3||Morbid obesity|
|50 and over||Super-morbid obesity|
The higher the BMI, the greater the health risks and the greater the likelihood of early, premature death.