Understanding your health and weight: Body mass index (BMI)
There are many things that affect our weight and health. These include the things that have happened to us and the things that we do.
The things that have happened to us:
where we live
access to services
The things that we do:
what and how much we eat and drink
our physical activity levels
time spent being inactive
previous attempts to lose weight
It is difficult to know what an individual’s ideal weight should be.
What is body mass index (BMI)?
BMI is used to categorise people’s weight. BMI charts are mainly used for working out the health of populations rather than individuals.
Within a population there will always be people who are at the extremes (have a high BMI or low BMI).
A high or low BMI may be an indicator of poor diet, varying activity levels, or high stress. Just because someone has a ‘normal BMI’ does not mean that they are healthy.
BMI doesn’t take account of body composition, for example, muscle, fat, bone density. Sex and other factors which can impact your weight can also lead to an inaccurate reading. As such a BMI calculation is not a suitable measure for some people including children and young people under 18, pregnant women and athletes.
Your BMI will fit into one of 5 bands:
under 18.5– This is described as underweight.
between 18.5 and 24.9– This is described as the ‘healthy range’.
between25 and 29.9– This is described as overweight
between 30 and 39.9– This is described as obesity
40 or over– This is described as severe obesity
If you have lost weight because you have been poorly or not eating very much you could ask your GP or health professional for help. If you don’t know why you have lost weight, see your GP or health professional.
Results of 25 and over are described as a ‘higher BMI’ and may be just one of the many reasons some of us are at higher risk of some health conditions, including type 2 diabetes.
The BMI ranges are slightly different for people from South Asian, Chinese, African-Caribbean and black African backgrounds. People from these backgrounds may be at higher risk of health problems at a lower BMI than people from other ethnicities.
For a lot of people, achieving a BMI within the ‘healthy range’ is not realistic. Whatever your weight there may be changes you want to make to improve your health, making a few small sustainable changes to your lifestyle can improve your health. Losing a small amount of weight, 5-10%, and maintaining this weight loss can have a significant positive impact on your overall health.We have aself-managed 12 week weight management programmeavailable if you feel you are able to manage your weight without the support of a health professional
If you are concerned about your weight you should contact your health professional.
Why your weight range is important
Health problems associated with a BMI in the obesity range include:
type 2 diabetes
issues with fertility in women
high blood pressure
fatty liver disease
Health problems associated with a BMI in the underweight range include: