Checking your weight
To check you’re a healthy weight, you need to measure your waist size and calculate your body mass index (BMI), see section below. You can control your waist size and BMI through healthy eating and physical activity. Your risk of developing serious health conditions increases if you don’t stay a healthy weight.
Healthy waist sizes for men
Your waist size depends on your race. A healthy waist size for European men is up to 37 inches.
A bigger waist size increases the risk of developing:
People with a waist size of 40 inches or more are likely to be overweight or become obese, though these measurements are for general population groups and some people will fall outside this range, such as athletes or others whose bodies have a high muscle content. A waist size of 40 inches or more further increases the risk of developing one of the health conditions above.
For Asian men, a healthy waist size is up to 35 inches. Those with a waist size bigger than 35 inches are at higher risk of developing one of the health conditions above.
Healthy waist size for women
A healthy waist size for a woman is up to 31.5 inches. A Caucasian woman with a waist size over 31.5 inches is at risk of developing:
If their waist size is over 35 inches, the risk of developing one of the above conditions is very high.
For Asian women, their risk is very high if their waist size is over 32 inches.
How to measure your waist size
To measure your waist size you need to use a standard tape measure. To measure:
- find the top of your hip bone and the bottom of your ribs
- place the tape measure midway between these points
- stand straight and breathe out naturally
- keep the tape measure snug but not tight around your waist
write down the result
Your body mass index (BMI)
Your ideal weight varies according to your height. Your body mass index or BMI is calculated using your weight and height measurements.
This BMI calculation is only for adults. There is a different calculation for a child’s BMI.
By calculating your BMI, you will have an indication if you are:
- underweight
- around the right weight for your height
- overweight
Measuring your BMI
Measure your weight in kilogrammes and divide it by your height in metres squared. For example, if you weigh 65 kilogrammes and are 1.73 metres tall divide 65 by 2.99 (1.73 x 1.73). Your BMI is 21.7
You can also calculate your BMI using the BMI calculator on the choose to live better website
What your BMI means
For most adults a BMI of:
- under 18.5 is underweight
- 18.5 to 24.9 is ideal
- 25 to 29.9 is overweight
- 30 to 39.9 is obese
- 40 or more is very obese
If your BMI is 25 or more, you’re overweight. This can increase your risk of health problems. Ask your GP for advice about losing weight.
If your BMI is less than 18.5, you might need to gain weight. Ask your GP for advice. Being underweight can also increase your risk of health problems, such as:
- brittle bones
- absent periods in women
- iron-deficiency anaemia
Accuracy of BMI
Muscle weighs more than fat. Very muscular people, such as heavyweight boxers, weight trainers and athletes may be a healthy weight even though their BMI is classed as obese.
Your ethnic group can also affect your risk of some health conditions. For example, adults of Asian origin may have a higher risk of health problems at BMI levels below 25.
You should not use BMI as a measure if you're pregnant. Ask your midwife or GP if you're concerned about your weight.
Losing weight
If you plan to go on a healthy eating plan to achieve gradual weight loss, you may want to seek advice from your GP beforehand. They can offer you help, support and advice before you start.
Commercial weight loss programmes that operate in Northern Ireland, such as Slimming World, Weight Watchers and Unislim, offer weekly weigh-ins, education and support and research has shown they can be an effective way to lose weight. There is a weekly cost to go to the sessions.
Online tools and apps can also help you set weight loss and exercise goals along with providing information on healthy lifestyle choices such as recipes, activities, and tried and tested hints and tips.
Some of the websites that may be of interest include:
- Choose to Live Better (Public Health Agency website)
- NHS Choices: Lose weight
- British Dietetic Association: Weight Wise website
Talk to your GP before beginning a weight loss programme if you have a long-term health condition, such as type 2 diabetes or heart failure.