Control your weight

Lady on scales

Controlling your weight helps to improve your overall health

Being overweight increases the work the heart has to do, causes high blood pressure, and leads to abnormal levels of fat in the blood. It is also associated with diabetesrespiratory disease, gall bladder problems and some cancers.

Being able to control your weight and keep it within healthy levels can reduce your risk of cardiovascular disease and prevent chronic disease from worsening. 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 your weight is within the normal range.

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.


  • 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:

18.5 – 25 Ideal weight
25 – 30 Overweight
30 – 40 Obese
>40 Very obese
<18.5 Underweight


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.

Your BMI is a less accurate indicator of risk if you are an athlete or very muscular. This is because the weight of your muscles may put you in a higher BMI category even if you have a healthy level of body fat.

Your BMI is a ratio of your weight in relation to your height. It is not a direct measurement of body fat, and therefore does not tell you about the distribution of your body fat.

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.

These waist measurement figures are a general indicator of a higher risk of health problems:


Waist Measurement Category
  • 37 – 40 inches (92.5 – 100cms)
  • >40 inches (>100cms)
  • Overweight
  • Obese
  • 32 – 35 inches (80 – 87.5 cms)
  • >35 inches (>87.5 cms)
  • Overweight
  • Obese

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, i.e. be 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 / she can refer you to a dietician 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.
Back to top