[lovediet]

Sorry if this topic has been addressed before, I didn't see it when I was searching.

I've been working out at Curves for the last 3 months. Every month you are required to weigh in and they measure you and give you a little scanner thing that calculates your body mass index that you hold at arms length.

The latest measurement from the beginning of Oct had me with a BMI of 31. I went home to look the figure up online and it put me in the OBESE category!

Now, I am no expert, but I would hardly classify myself as obese. I am 5'3 and 3/4 tall (I usually round up to 5'4,) and at the last weigh-in (the same one where my BMI was calculated,) I weighed 156 lbs. I am 23 years old. I wear a pants size 10-12 in petites.

So while I'd agree that I may be overweight, I don't think I fit the profile of obese. I've tried calculating it online and I get figures anywhere in the 24.5-29 range.

Can anyone help shed light on this? Is this really a good indicator of body fat?

[mandalinn82]

Well, you have several questions here. First of all, the BMI is a set calculation - it makes no sense that you'd get a 31 from Curves and a 25.4 with some other calculator. There is a set formula involved. At 156 lbs, someone who is 5' 3.75" has a BMI of 27, in the middle of the "overweight" range. The formula stays the same, so your number won't change unless your height or weight changes.

As for whether BMI is a good indicator of body fat, it depends. It has known inaccuracies for certain groups (Very muscular groups like athletes, or very non-muscular groups like the elderly, for example). Because it doesn't take into account your age, sex, frame size, etc, it can only provide you with an AVERAGE value for all people with the same height and weight as you.

It sounds like, though, you didn't get measured for BMI at Curves - you got measured for actual body fat percentage, with a bioelectrical impedence device. The accuracy of these devices depends on a good number of things (the device itself may be a less accurate or more accurate one, etc). There are more accurate ways to measure body fat percentage, like hydrostatic weighing, but they are more expensive and harder to find.

[kelly315]

I got a BMI of 26.8 when I put your info into a couple of calculators, and I'd be surprised if it's wrong. Maybe you just had calculation problems before. I wouldn't say that you're obese, either. BMI is a very finicky system, and it usually asks people to be thinner than would be attractive or healthy-looking for them. If I were you, I would just try to work on getting where I want to be physically and weight wise, and not worry too much about the bmi.

[lovediet]

Thanks for the comments.

mandalinn-I bet you were right and Curves measures BODY FAT % instead. That would make more sense. The number was never really fully explained to me. Thanks for the insight!

kelly- I think that is a good piece of advice! I actually RAISED my goal weight 10 lbs, because I look better than I thought I would in the 150's. Perhaps this is because I have been working out, so the 156 I used to be when not working out seems to look different than I do now..