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Obesity in adults

Published by Bupa's health information team, May 2009.

This factsheet is for people who have obesity, or who would like to know more about it.

Obesity is a condition in which excess body fat seriously affects a person's health. It happens when a person eats too many calories (energy) and doesn't do enough physical activity. Obesity increases the risk of a number of health problems including cancer, heart disease and type 2 diabetes.

About obesity
Complications of obesity
Causes of obesity
Diagnosis of obesity
Treatment of obesity
Questions and answers
Related topics
Further information
Sources

About obesity

If you regularly take in more calories (energy) than you use up, the extra energy is stored in your body as fat. You will start to put on weight and eventually become obese.

The number of obese adults in the UK has tripled since 1980. In 2006 around seven out of 10 men and six out of 10 women in the UK were either overweight or obese.

Complications of obesity

If you're overweight, you're at risk of developing health problems. These include:

type 2 diabetes
high blood pressure
aching joints and osteoarthritis
coronary heart disease
some types of cancer
sleeping problems such as sleep apnoea
back pain
breathlessness
snoring and difficulty sleeping

Women who are obese are more likely to have problems during and after pregnancy. If you're obese it can cause low self-esteem and poor body image.

Causes of obesity

An unhealthy diet combined with a lack of exercise are the main causes of obesity. Fatty foods, sweet foods and sugary drinks are likely to cause weight gain if you eat or drink them regularly. This is because they contain lots of calories and often few other nutrients. Large portion sizes can increase your chances of developing obesity.

If you were overweight or obese as a child, or if there is a family history of obesity, you're more likely to be obese as an adult. Genetic factors could play a role in this.

Occasionally medical conditions and medication may cause you to put on weight.

Diagnosis of obesity

If you think you're overweight, you should visit your GP. He or she will ask you about your symptoms and may check your weight and height to calculate your body mass index (BMI). This measurement is used to work out if you're a healthy weight for your height. You can calculate your BMI by dividing your weight by your height, then dividing the answer you get by your height again. To work out your BMI accurately and easily, see our BMI calculator.

Using the BMI measurement system, if you have a BMI of:

25 to 29.9 - you're classed as overweight
30 to 39.9 - you're classed as obese
over 40 - you're classed as severely obese

If you have a lot of muscle, your BMI may not be an accurate measurement of whether you need to lose weight. If you belong to a certain ethnic group (for example, if you're of Asian descent), the BMI ranges specified previously may not be appropriate for you. You should talk to your GP about your BMI.

Your GP may also take your waist measurement. Where you store fat on your body is an important indicator of whether or not there is a risk to your health. If you carry the extra weight around your middle (an 'apple shape'), rather than your hips and thighs (a 'pear shape'), you're at an increased risk of obesity-related diseases. Your health may be at risk if you're a man with a waist measurement of 94cm (37 inches) or more, or a woman with a waist measurement of 80cm (32 inches) or more.

Your GP may measure your blood pressure and offer a blood test to measure your cholesterol and blood sugar levels. He or she will give you advice on the support and treatment that is available to you. If you have health problems related to obesity, your GP will provide the necessary treatment.

Treatment of obesity

The best way to achieve a healthy weight is to make long-term improvements to your diet and eating habits, while increasing the amount of physical activity you do.

You're more likely to keep the weight off for good if you lose weight slowly. This allows time for new healthier eating habits to become part of your everyday life. It's important that you're realistic about the amount of weight you wish to lose. Most people try to lose large amounts too quickly and then become disheartened when they don't reach their target goal. The recommended rate of weight loss is 0.5 to 1kg (1 to 2 lbs) per week. You will need time to practise new eating patterns and learn new approaches to eating.

Losing weight can be difficult, so consider whether now is a good time to begin. If you're under pressure at work, or home life is difficult, it may be better to plan to start losing weight in a few months time once you can focus more on yourself.

A healthy well-balanced diet

Eating more calories than your body needs will cause you to put on weight because the extra energy is usually stored as fat. It's important that you follow a balanced diet and control portion size to maintain a healthy weight.

Base your meals on starchy foods such as potatoes, pasta, bread and rice. You should chose wholegrain varieties if you can. Starchy foods are a good source of energy and the wholegrain options are a good source of fibre.
Try to limit the amount of food high in fat and sugar, such as cakes, biscuits and butter. You should cut off any visible fat on meat and choose lean options.
Introduce more fruit and veg into your diet so that you eat at least five portions a day. You could snack on fruit during the day and have a portion of vegetables with your evening meal.
Aim for at least two portions of fish a week, including a portion of oily fish, such as salmon, mackerel, or fresh tuna.
Eat breakfast because it gives you energy and is a good start to the day. It also provides essential vitamins and minerals.
Alcohol is high in calories so reducing the amount you drink can help control your weight.
Water is the best drink. You could try flavouring water with low calorie squash or ice and lemon. Choose low sugar drinks instead of high calorie drinks such as fizzy pop, squash and milkshakes. Drinks don't help satisfy your appetite so it is easy to take in too many calories without realising it.
It's fine to snack but make sure you choose healthy options such as fruit and low fat yoghurts. Snacking can help you manage your appetite so that you eat smaller portions at main meals.

Changes to eating habits

It can be difficult to make changes to your diet. Here are a few suggestions:

Watch your portion sizes. Avoid situations where you are more likely to eat too much. Some examples are eating at the same time as doing something else, such as watching TV or reading. You're also more likely to overeat when you're tired, stressed or when you're very hungry.
Eat slowly, chew your food well and concentrate on what you're eating.
When you eat out, try to choose healthier options. You should go for dishes that are grilled, steamed or boiled. Choose sauces that are made from tomatoes or vegetables instead of cream or cheese. Order vegetables or a side salad with your meal. If necessary, eat a healthy snack beforehand to avoid overeating.
Try not to skip meals as this will make you hungry later on. Eat three balanced meals and include a starchy food, vegetables or salad, and some protein (meat, fish, cheese, egg or beans).

Fad diets

A fad diet involves eating a very limited range of foods. These diets aren't healthy and although they may lead to short-term weight loss, you will always put the weight back on as soon as you return to your normal diet. There is no quick fix available. If you want to lose weight and keep it off you need to make healthy changes to your diet and lifestyle. Try to practise these new behaviours until they become part of your everyday routine.

Physical activity

Performing 30 minutes of moderate intensity exercise at least five times a week can control your weight and improve your health. Moderate exercise needs to be intense enough to make you feel short of breath, warm and to raise your heart rate. If you haven't been physically active for a while, you can do separate sessions of 10 or 15 minutes to help you reach the 30 minutes target. You may need professional supervision and if you're unsure then get advice from your GP.

There are lots of ways to increase the amount of physical activity that you do. You don't need to join a gym to achieve your 30 minutes target. You can carry out everyday activities such as:

gardening, washing the car and doing housework at double time
getting off the bus a stop earlier or walking up stairs instead of taking the lift
planning activities with your friends and building up the amount of activity that you do so that it becomes part of your routine
walking instead of driving short journeys

It's important that you find an activity you enjoy to help you stay motivated. If you find exercise boring on your own, invite a friend to join in with you or join a local club.

Try to reduce the amount of time that you watch the TV or the computer.

Medicines

If you have been following a healthy diet and increased your physical activity, but have still not seen any improvement in your weight, your GP may prescribe you a medicine to help you lose weight. Sibutramine can make you feel full after eating small portions of food. Orlistat stops your body absorbing all the fat from your food.

The medicines are recommended for people with a BMI of 30 or higher. If you have health problems associated with obesity, your GP may prescribe you medicine if your BMI is 27.

Your GP will discuss any potential benefits and limitations of the medicine. You will also be given information about patient support programmes. It's important that you have regular follow up appointments with your doctor.

Surgery

Occasionally surgery is recommended for obesity. The most common types of surgery are gastric bypass and gastric banding. They involve reducing the size of the stomach so that you eat less, or bypassing part of the gut so that your body absorbs less food. Surgery is recommended for people with obesity who:

have a BMI of 40 or higher, or have a BMI between 35 and 40 with a disease that could be improved with weight loss (eg diabetes or high blood pressure)
have tried other suitable ways of losing weight without any success
are fit for surgery
commit to a long-term treatment programme

If you have a BMI of 50 or more, surgery may be the first option. If your GP recommends surgery, he or she will refer you to a specialist. The specialist will talk to you in more detail about the benefits and limitations of the surgery. Once the operation is completed, you will work with a specialist obesity team who will help you to make changes to your diet.