Obesity and Overweight

Body mass index
Your body mass index (BMI) is a good estimate of how much of your body is made up of fat. It relates your weight to your height. You can work out your BMI by dividing your weight (in kilograms) by the square of your height (in metres).

So, for example, if you weigh 70 kg and are 1.75 metres tall, your BMI is 70 / 1.75 x 1.75, which is 22.9. Alternatively, your practice nurse can measure and weigh you, and tell you your BMI.

Waist size
Your increased health risk is greater when the extra fat is mainly around your waist ('apple shaped'), rather than mainly on your hips and thighs ('pear shaped'). As a rule, a waist measurement of 102 cm or above for men (92 cm for Asian men) and 88 cm or above for women (78 cm for Asian women) is a significant health risk.

In short, the heavier you are, the longer your carry the extra weight, and the more the fat is around your waist, the greater your health risk.

How common is obesity and overweight?

More than half the adults in the UK are heavier than recommended. About 2 in 5 adults are overweight, and about a further 1 in 5 are obese. The number of obese people in the UK is rising, particularly among young adults. Since 1980, the number of obese adults in the UK has nearly tripled. This has been called the 'obesity epidemic'.

What are the benefits of losing weight?

It is difficult to measure how much 'quality of life' is improved if you lose some weight. Many people feel better, and have more energy. Some people notice an improvement in their self-esteem.

There are also definite health benefits from losing some weight. Many diseases are more common in obese and overweight people, and you are less likely to develop them if you lose some weight. They include: diabetes, high blood pressure, stroke, heart problems, some types of cancer, arthritis of the back and legs, gallstones, menstrual problems, incontinence of urine, breathing problems, some complications of pregnancy, and depression.

What is more, for most obese or overweight people, much of the health benefits come with losing the first 5-10% of your weight. This is often about 5-10 kg. (10 kg is about one and a half stone.) If you are obese, on average, if you reduce your weight by 10%:

• You are much less likely to develop the conditions listed above, such as diabetes.
• If you already have high blood pressure, osteoarthritis, or diabetes, these conditions are likely to improve. If you are taking medication for these problems, you may need a reduced dose.
• Your chance of dying at any given age is reduced by about 20%. This is mainly because you are less likely to die from heart disease, stroke, diabetes, or obesity related cancers.