bmi

[MiniN]

Hi,

I once had my Body Mass Index calculated using a little machine that i placed my two thumbs on. are these accurate in reading your BMI? i'm only asking as mine came back as quite high despite being quite slim (some weighing scales say i'm actually slightly underweight- but still in normal range).

so is it possible to be slim but have a high BMI?

thanks

[sophie_1003]

Go to google and type in bmi calculator or something like that and do it on there, if it matches your machine then its accurate. BMI isnt a very good way of measuring healthy weight as muscle weighs more than fat so if you're quite muscly or even toned, the 'excessive' weight could be that rather than fat.

[jake-the-peg]

Given that BMI is a ratio between you height and weight I can't see how any machine can work either of those out from your thumbs!

As Sophie says BMI is a pretty dumb measurement.

Try some of the body fat calculators like this:
http://www.healthstatus.com/calculate/bfb

They let you enter in some measurements of your body and estimate how much of your weight is fat.

Then have a look here:

http://www.healthchecksystems.com/bodyfat.htm

to see whether or not you need to worry about it

[MiniN]

I couldn't personally figure out how it worked either. i told the lady my height and weight then i think this machine was supposed to measure how much in your bod was fat and what was muscle but i doubt someone who is naturally slim would have a stupidly high bmi, isnt that impossible?

[jake-the-peg]

Pretty much - sounds like electronic quackery to me!

[Miss Inquiry]

It sounds like you had your body fat percentage taken not your BMI.

The machine works by passing an electronic signal through your body (often done through your bare feet), the time it takes for the current to pass back determines what % of your body is fat, using a clacualtion of your weight, height and the speed of the electonic signal. The healthy range for a woman is between about 23% and 33%, it is a lot lower for men.

Could this be a plausible explanation?

[MiniN]

that sounds like it rings bell Miss Inquiry. but how would someone naturally slim have a high fat percentage? any ideas?

[Miss Inquiry]

Women have a much higher fat % than men, our breasts, bums, thighs store fat for the process of reproduction and looking after childrenand our vital organs. Very thin people can have a high fat % and visa versa. Depends on what you eat, how quickly your metabolism works, how muscly you are. If your over 33% your classed as unhealthy, and 33% is pretty high.