Overweight and obesity in adults

How to tell if you’re living with overweight or obesity

Body mass index (BMI)

You can find out if you are a healthy weight by working out your body mass index (BMI) using the BMI calculator.

For most adults:

• a BMI of 25 to 29.9 is overweight
• a BMI of 30 or more is obese

If you are from a South Asian, Chinese, other Asian, Middle Eastern, Black African or African–Caribbean background you're at risk of health problems with a slightly lower BMI, so:

• a BMI of 23 to 27.4 is overweight
• a BMI of 27.5 or higher is obese

The BMI calculator cannot tell the difference between muscle and fat. For example, if you have a lot of muscle, it's possible the BMI calculator may put you in the overweight or obese category even if you do not have a lot of body fat.

Waist to height ratio

If your BMI is under 35, you can use the waist to height ratio calculator to help you understand if you're carrying too much fat around your tummy.

You should try to keep your waist size to less than half your height.

Risks of living with overweight and obesity

Living with overweight and obesity increases your risk of developing many other serious health conditions, including:

• type 2 diabetes
• heart disease
• stroke
• high blood pressure
• some cancers, such as breast cancer, womb cancer and bowel cancer
• osteoarthritis
• fatty liver disease

Living with obesity is likely to lower your life expectancy by between 2 and 10 years.

It can also cause day-to-day problems such as:

• breathlessness
• difficulty moving around
• feeling very tired (fatigue)
• joint and back pain
• snoring
• mental health problems, such as feeling very low (depression)

How to lose weight

Making changes to your lifestyle can help you lose weight and maintain a healthy weight.

To lose weight try to:

• eat and drink fewer calories than your body uses
• do more physical activity to burn more calories

On average, women use around 2,000 calories a day, and men use around 2,500 calories a day.

Find out more about understanding calories

Treatments to help you lose weight

It can be hard to lose weight and you may need extra support or treatment to lose weight and keep the weight off.

A GP can give you advice about losing weight safely and refer you for treatment, including:

• weight management programmes
• medicines
• surgery

A GP can also help you get support for any other conditions that might be affecting your weight, such as mental health conditions.

Weight management programmes

Weight management programmes can help support you to lose weight safely and keep the weight off.

They might include:

• 1 to 1 coaching
• cognitive behavioural therapy (CBT)
• group support
• online exercise classes
• healthy eating advice and recipes

You can self-refer for some weight management programmes.

If you need a lot of extra support to lose weight, you may be referred to a specialist weight management service

You may also be able to get support from a dietician to follow a very low calorie diet (under 800 or 1200 calories).

Very low calorie diets are not suitable or safe for everyone. They are usually only recommended if your weight is affecting other health conditions and you need to lose weight quickly.

If you have other health conditions that are affected by your weight such as high blood pressure or type 2 diabetes, you may be offered specialist support such as the NHS digital weight management programme.

Weight loss medicines

Depending on your BMI, and if you have any other health conditions affected by your weight, you may be able to have medicines to help you lose weight.

Medicines for weight loss work in different ways. They can:

• reduce your appetite and help you feel fuller for longer (GLP-1 and GIP agonists such as semaglutide, tirzepatide and liraglutide)
• stop your body absorbing as much fat from foods (orlistat)

Weight loss medicines are usually prescribed alongside diet and lifestyle advice.

You'll need to eat a balanced diet with fewer calories and do regular physical activity while taking them.

After you stop taking the medicines you should be offered support to help you stay a healthy weight.

Weight loss surgery

Weight loss surgery, sometimes called bariatric surgery, is surgery that makes your stomach smaller so you do not eat as much food.

You may be offered surgery if:

• you have a BMI of 40 or over
• you have a BMI of 35 or over and have other health conditions that could be improved by weight loss, such as type 2 diabetes or high blood pressure

If you are from a South Asian, Chinese, other Asian, Middle Eastern, Black African or African–Caribbean background, you may be offered surgery if:

• you have a BMI of 37.5 or over
• you have a BMI of between 32.5 and 37.4 and have other health conditions that could be improved by weight loss, such as type 2 diabetes or high blood pressure

You'll have the surgery in hospital and usually go home 1 to 2 days after. Recovery time is usually 3 to 4 weeks.

After surgery you'll have regular check-ups for 2 years to make sure you're eating healthily and doing regular physical activity.

Causes of overweight and obesity

You put on weight when you your body turns extra calories from food and drink into fat.

This is often caused by:

• not doing enough physical activity to use up calories from food and drink
• eating and drinking more than your body needs, especially food and drinks that are high in fat and sugar

You may also find it harder to stay a healthy weight if you:

• have an eating disorder or other mental health condition, such as depression
• have a health condition or disability that makes it difficult to be physically active
• have a learning disability
• have a health condition that causes weight gain, such polycystic ovary syndrome (PCOS), an underactive thyroid gland or Cushings syndrome
• take certain medicines including some steroids, antidepressants and beta blockers
• have genes that make you more likely to gain weight
• are over 55 years old
• are menopausal or perimenopausal

Speak to a GP for advice if you have a condition that makes it harder to stay a healthy weight.

Help and support for overweight and obesity

Overweight and obesity can be a difficult to live with, both physically and emotionally.

You can find out if you can get any help with day-to-day living, such as help to move around, in the social care and support guide.

You can get support to make lifestyle changes in the NHS Better Health guide.

You may also find it helpful to join a local support group or find an online support group through a charity such as Obesity UK.

Obesity UK

Information and support for anyone affected by overweight and obesity.

• Website: www.obesityuk.org.uk
• Obesity UK: support groups