Obesity means carrying extra body fat that can affect your health. It is very common. Around 1 in 4 adults in England live with obesity.
Obesity is recognised as a long-term health condition. Like other conditions, it has many causes, and it can be treated and managed with the right support.
How obesity is measured
Doctors usually use your body mass index (BMI), which compares your weight with your height. You can work yours out with the NHS BMI calculator.
| BMI | What it usually means |
|---|---|
| 18.5 to 24.9 | Healthy weight |
| 25 to 29.9 | Overweight |
| 30 to 39.9 | Obesity |
| 40 or more | Severe obesity |
If you are of South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean heritage, health risks start at a lower BMI. For you, 23 is the start of overweight and 27.5 is the start of obesity.
Your waist also matters. As a guide, try to keep your waist to less than half your height.
Why it matters for health
Obesity raises the risk of many conditions, including:
- type 2 diabetes
- high blood pressure and heart disease
- osteoarthritis, especially in the knees and hips
- some cancers
- sleep apnoea and breathing problems
- low mood and anxiety
Losing even a small amount of weight, such as 5% of your body weight, can improve your health and lower these risks.
What causes obesity?
Many things play a part, often together:
- genes, which affect appetite and how your body stores fat
- the food around us, which is often cheap, high in calories and heavily advertised
- less active lives, with more sitting at work and at home
- some medicines, such as some antidepressants, steroids and diabetes medicines
- health conditions, such as an underactive thyroid
- sleep, stress and mental health
- money and time, which affect what food you can buy and cook
Getting support
You do not have to do it alone. Your GP can check your health, and may refer you to an NHS weight management programme or, for some people, specialist treatment. See obesity treatment and support.
Common questions
Is BMI a good measure?
BMI is a useful starting point, but it does not tell the whole story. It cannot tell muscle from fat, for example. Doctors often also measure your waist, because fat around the middle is linked to more health risks.
Is obesity my fault?
No. Weight is affected by many things you cannot control, including your genes, your hormones, some medicines, your health, your income and where you live. Blame does not help anyone. Support does.
Sources we used
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