What Is BMI?

Fitness | Lifestyle

Posted on August 07, 2015 by Kate Halsall

bmi

BMI or Body Mass Index is used by health professionals as an indicator or screening tool to assess any potential weight problems in a person. It is designed to classify whether someone is a healthy weight for their height. But is BMI the best way to classify whether someone is a ‘healthy’ weight?

Under 18.5 Underweight
18.5 – 25 Healthy Weight
25 – 30 Overweight
30 – 40 Obese
Over 40 Severely obese

It’s important to note, that the term “obese” when related to BMI is not about how you look, it’s used to describe your risk of health problems.

The main question which surrounds BMI is whether it is an accurate assessment of body composition and health. Here’s some pros and cons to help you decide:

Pros

  • It’s a standardised calculation used globally -but you could also argue that whilst it’s standardised, due to the con’s below, it’s not the most accurate measurement.
  • Simple calculation based on weight and height for an individual
  • It can be an early indicator of potential health problems as a result of weight

Cons

  • Does not take into consideration age, ethnicity or sex
  • Does not take into consideration Fat Mass and Lean Body Mass (it groups muscle and fat into one entity), so athletic built individuals or people with lots of muscle can be “obese” based on the BMI calculations, especially if they are small in height.
  • BMI is not applicable if you are pregnant
  • Does not directly measure body fat, you need other methods to determine exactly how much body fat you have.

Ultimately, if a person doesn’t regularly participate in fitness or exercise, BMI can be a good indicator of their health/body composition. However, it’s not just weight that can indicate potential health problems! BMI should never be used as a standalone tool as there are too many other factors which can influence the result.

We know that age, sex, lean body mass, hormones etc can affect our body fat and where it is stored. Other diagnostic tools, such as having your body fat measured using skinfold calipers, should be used to get a more accurate picture about whether you are carrying excess body fat which may cause health issues.

 

For More Information:

http://www.nhs.uk/chq/Pages/3215.aspx?CategoryID=52

http://www.medicalnewstoday.com/info/obesity/what-is-bmi.php