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Controlling your weight

Keeping a healthy body weight is really important if you are living with a long-term chest condition.
Your doctor or nurse will be able to work out what is a healthy weight for you. 

If you are overweight, your body will have to work harder to get the oxygen it needs. This will make you feel more breathless and tired.

If you are underweight, you may be at greater risk of infection, have less energy and feel less able to cope with your health. If you notice you are losing weight, or you are having trouble eating, speak to your doctor. You may be referred to a dietitian who can advise you on your diet and meeting your nutritional requirements.

It is a good idea to be as close as you can to your ideal weight, this is best achieved by controlling your weight through a balance of eating healthily and keeping as active as you can. Your body mass index (BMI) and your waist measurement are both accurate ways of assessing if you are overweight.

Body mass index (BMI)

Body mass index (BMI) is a measurement of body fat (based on height and weight) that applies to both adult men and women.

The number is calculated by dividing your weight in kilograms by your height in metres squared (m²). This is already done on some weight charts. Ideally you should aim for a BMI in the healthy weight category (18.5 to 25)

  • Your BMI = Your weight (kg) ÷ Your height (m) × Your height (m)

In the UK the following levels apply to help you work out what your BMI means:

BMI (kg/m²)  Category
Less than 18.5 Underweight
18.5-25 Healthy weight
25-30 Overweight
Over 30 Obese

Follow this link for an example of a website that will calculate your BMI for you. You can also download apps for your phone to monitor your weight and BMI.

Waist measurement

The measurement of your waist size (circumference) is increasingly being regarded as a more accurate indicator of risk than your BMI. It provides information about where your body fat is stored. If you carry extra weight around your stomach (‘central obesity’) you are at increased risk of heart disease and stroke. Ideal healthy waist measurements for men and women are:

  • Less than 32 inches (80cm) if you are a woman
  • Less than 37 inches (94cm) if you are a man

Tips if you are underweight

Some people with chest conditions get tired / breathless easily and find cooking and eating difficult. As a result you may not be meeting your energy needs and you may be underweight.

If you are underweight try to:

  • Eat small amounts as often as possible.
  • Snack on high energy and protein foods throughout the day. This includes  nuts, crisps, dried fruit, cheese.
  • Choose full fat or high energy options such as full-fat milk or cream.
  • Add extra energy to your food by adding high calorie ingredients. For example add cheese to pasta
  • Drink fluids with a straw as this can be less tiring than using a cup.
  • Include high-calorie fluids: try fruit juice, high-energy drinks, milk, milk-based coffee or chocolate drinks, or supplement drinks. All these are available from your local chemist.

Tips if you are overweight

You will gain weight if you take in more calories from food than you use up (calories are a measure of energy). When this is balanced your weight will remain stable.

So, to lose weight you have to eat fewer calories and use up more energy by being more physically active.

  • Reduce the fat in your diet and avoid sugary foods like biscuits, cakes, soft drinks and confectionery as these are extra calories that do not keep away hunger or provide nutrients.
  • Speak to your doctor if you feel that you need professional help to lose weight. He or she can refer you to a dietitian if necessary.
  • The best way to lose weight is slowly. A gradual weight loss of around 0.5–1kg (1–2lb) a week is recommended. If you lose weight too quickly you will be far more likely to put the weight back on again.
  • You are also more likely to be successful if you lose weight with other people, e.g. by joining a slimming club. You can attend weekly classes or gain support online.
For more information on losing weight only, see the CHSS factsheet Losing weight (PDF)