Author: Lesley Smyth (Obesity tutor/presenter/expert)
Obesity is defined as a ‘medical condition in which excess body fat has accumulated to the extent that it may harm health’ (NHS, 2012). It is a complex multifactorial chronic disease that develops from an interaction of genotype and the environment. Preventing and managing obesity is a complex problem with no easy straightforward answer.
Obesity has a severe impact on the health of individuals both physiologically and psychologically, with the risk of complications from secondary conditions a major concern. It’s also linked to Metabolic Syndrome (also known as syndrome X), which is a medical term for clustering of symptoms/medical disorders that, when presented together increase the risk of developing diabetes type 2 or cardiovascular disease.
In 2006 International Diabetes Federation (IDF) consensus worldwide definition is central obesity defined by waist circumference AND any two of the following…
Classification |
BMI (KG/M2) |
Risk of secondary conditions |
Underweight |
<18.5 |
Low (other health risks may be associated with low BMI) |
Healthy weight |
18.5 - 24.9 |
Average |
Overweight (pre-obese) |
25 - 29.9 |
Increased |
Obesity, class 1 |
30 - 34.9 |
Moderate |
Obesity, class 2 |
35 - 39.9 |
Severe |
Obesity, class 3 |
>40 |
Very severe |
Assessment of the health risks associated with overweight and obesity in adults should be based on BMI and waist circumference as follows…
Weight classification |
BMI (Kg/M2) |
Men > 102cm (40’) Women > 88cm (35’) |
Underweight |
<18.5 |
- |
Normal |
18.5 - 24.9 |
- |
Overweight |
25 - 29.9 |
High |
Obesity class |
||
1 |
30 - 34.9 |
Very high |
2 |
35 - 39.9 |
Very high |
3 |
>40 |
Extremely high |
Disease risk* relative to normal weight and waist circumference *Increased waist circumference also can be a marker for increased risk, even for individuals of normal weight. |
Further metabolic risks associated with Obesity:
Obesity not only affects our bodies but also our society.
Use the online BMI calculator to check your BMI