Need to lose weight?

Why a healthy weight is important

If your BMI or waist circumference is above the healthy range you're at increased risk of diabetes, cardiovascular disease and certain cancers such as colon, prostate and breast cancer.

You're also more likely to experience joint problems and back pain, and may find you become breathless and have difficulty sleeping.

The more weight you gain, the more severe these problems may become.

You can work out your BMI with our calculator.

How to lose weight

Losing weight depends on energy balance. If you consume more energy from food and drink than you burn through maintaining your body's functions (metabolism) and physical activity, you'll gain weight.

Cutting calories by reducing how much you eat and drink, and increasing how much physical activity you do will make you lose weight.

If you reduce your daily energy intake to around 500 calories (kcal) below your energy requirements, you'll lose about 0.5kg (1lb) a week. This is a sensible rate of weight loss.

Are you ready to lose weight?

Before you start making changes to your lifestyle, it's important to ask yourself if this is the right time. Are you motivated to change?

The reasons you decide to lose weight will be personal to you. You might find you're more successful if you choose a relatively calm time in your life to start. Conversely, changes in your circumstances, such as a new job or house move, may be the key to your weight loss success.

Whatever you decide, make sure you're feeling positive and ready for the challenge.

Setting realistic goals

To lose weight - and keep it off - you'll need to make permanent changes to your diet and physical activity patterns.

Think carefully about your daily routine. Keeping a food diary may help you to identify patterns in your eating behaviour. This will help you to decide on realistic changes you need to make.

Set achievable goals and try to make modifications to your existing diet and how active you are. Drastic lifestyle changes will be difficult to maintain over time.

Aim to lose about five to ten per cent of your initial body weight over a few months. Research shows this kind of weight loss is achievable and will improve your health.

Once you've reached your goal, congratulate yourself and set another five per cent weight loss target.

This way, you'll feel good about achieving small steps, rather than getting down because it's taking you so long to lose a large amount of weight.

Sticking with it

You may lose more weight in some weeks than in others, but as long as your weight continues to decrease overall there's no need to worry.

If your weight stays the same for a week or two, don't abandon all you've achieved. Instead, focus on the amount and type of food you're eating and try to be a little more active.

Dr Susan Jebb last medically reviewed this article in June 2007.