Ask an expert

25 Feb 2009

BMI is dubious
Hi Diet Doc

My BMI is about 26 and I' m on Weigh-Less to lose some weight. Aiming for a BMI of 20-25 would put my goal weight at 57 - 70kg (1.68m tall). This range is enormous! Also, at 57kg I' ve calculated I would only have about 12% body fat which I think is unhealthy for an active late-20-something woman. I also don' t think the BMI takes into account one' s muscle mass at all. Is this really an objective measure of a " healthy"  weight? Surely a target body fat % or is better than setting a goal weight based on BMI?
Answer 415 views

01 Jan 0001

Dear Laser
The BMI is a tool that is used to estimate if someone is overweight or obese of within the normal range or anorexic. For your height of a weight of 62 kg would give you what is regarded as an 'ideal BMI for women". As you correctly state, an individual with a high percentage of muscle tissue may weigh more, but have a low body fat%. If your body fat % is already below 24% (the normal value for women who are not elite athletes), and your weight is around 62 kg, then you are probably in the peak of health and very fit. Setting a target body fat % only works with individuals who do physical exercise and have access to accurate methods of measuring this value.
Best regards
The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical examination, diagnosis and formal advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.
Voting Booth
Have you entered our Health of the Nation survey?
Please select an option Oops! Something went wrong, please try again later.
33% - 9323 votes
67% - 18741 votes