Is obesity a disease? What's behind it and why it isn't about willpower
Obesity is more than a few extra kilos: professional bodies see it as a chronic disease with many causes. What that means, how it's diagnosed and what health effects it can have.
- obesity
- basics
- health
In short
The World Health Organization and the German Obesity Society classify obesity as a chronic disease. It arises from an interplay of genes, hormones, environment, sleep, stress and life circumstances, not from a lack of discipline.
That view changes treatment too: away from short-term diets, towards long-term, medically grounded management of your weight.
How obesity is diagnosed
In everyday use, body mass index is the usual measure: a BMI of 25 or more counts as overweight, 30 or more as obesity. But BMI is only a rough guide. It doesn't distinguish muscle from fat or show where fat is stored.
That's why other measures are often added, such as waist circumference, blood pressure, blood sugar and blood lipids. Abdominal fat is considered especially relevant for metabolism.
Many causes, no blame
Body weight is regulated by a complex system of hormones and signals between the gut, fat tissue and brain. In some people that system is more strongly set to maintain or gain weight, and genetics plays a large part.
Add factors such as lack of sleep, stress, certain medicines, hormonal changes and an environment where energy-dense food is always available. And the body resists weight loss by turning up hunger, which explains why diets so often don't last.
Possible health effects
Obesity can raise the risk of a range of conditions. Not everyone with obesity develops them, and even moderate weight reduction can have benefits. They include:
- Type 2 diabetes and its early stages
- High blood pressure, raised blood lipids, cardiovascular disease
- Sleep apnoea
- Fatty liver
- Joint problems, for example in knees and hips
- Psychological strain, often worsened by stigma
Why classing it as a disease helps
Many people with obesity have been told for years that they just need to try harder. Classing it as a chronic disease takes that pressure off and opens the door to effective support: nutrition, movement, behavioural therapy and, depending on the situation, medicines or surgery.
As with other chronic conditions, it's about long-term management, not a quick fix.
Note
This Journal article offers general information. It is not a diagnosis, a prescription or a promise of any result. Whether treatment is suitable for you is decided by a doctor after reviewing your questionnaire. For acute or severe symptoms, contact your GP, the out-of-hours medical service (116117) or, in an emergency, 112.
Sources and medical review
Based on the World Health Organization's classification and the German S3 guideline on obesity. Educational only; does not replace a medical examination. Medical review pending.
- World Health Organization: Obesity and overweight fact sheet
- German S3 guideline on prevention and treatment of obesity (German Obesity Society)