BMI why is this soooooo off? - Weight Loss Message Board

matt1234567890 · 12-18-2007, 03:08 PM

About a week ago i went to a trainer to get my numbers taken and set up a plan. My body fat was 18% which he said was good. now after working out this week and droping about 5 pounds i was just wondering what kind of impact that made on my fat. I typed in my weight and hieght and body frame and it said i was at 27.5% body fat?!? so i toyed with the numbers a bit and for my current weight of 214 pounds and 6'2" i would either have to drop 54 pounds or grow to 6'11". I can say with 100% certainty to drop 54 pounds i would have to lose every bit of fat and muscle and maybe some bones.... and as for mantianing my weight on a nearly 7 foot person lol a stick is what i imagine. I also want to say that although i am now working out seriously i haven't in the past so i don't think that my muscle mass is a major factor. I was just wondering why this thing is so off, i understand that its a genral formal but still almost 10% off... and those "ideal" numbers... whats up?

kristy222 · 12-20-2007, 09:35 PM

I think you are highly confused. Body Mass Index (BMI) is NOT the same as percent body fat. They are two very different measurements. BMI is a number that reflects your weight to height ratio. It is your weight in kilograms divided by height in meters squared. The BMI numbers really don't *mean* anything on their own. You need to be able to interpret the numbers for them to mean something. Here is an interpretation of the BMI values:

BMI under 19 - considered underweight
BMI of 19-24.9 - ideal (considered to be 'normal' weight)
BMI of 25-29.9 - overweight
BMI of 30 or more - obese

So your BMI is 27.5 (NOT 27.5% body fat!!). This means that you are overweight, although not by much. To get to a BMI of 24.9 ('normal weight') at 6'2 you will have to weigh 193 lbs which means you need to lose 21 lbs.

Body fat percentage is the percent of FAT your body contains based on its total weight (which is also made up of bone, muscle, organ tissue, blood, etc).