BMI goes up the more muscley you become... which is why the table rates well toned athletes and bodybuilders as "obese". It's a fairly poor indicator of health and fitness when applied to individuals, since it was never designed to do that. (BMI was created as a tool to assess the generic health of very large pools of people for insurance purposes, but it breaks down in smaller pools and even more so on individuals).
Home scales that measure body fat % are, as the previous poster mentioned, very sensitive to water, and they can only measure your lower half since they send the current up one leg, and down the other. So, if you carry your weight unevenly (like everyone does), it won't be accurate. If you lose 10 lbs from your belly, back, and arms, and none from your legs, the scale will tell you that while you lost weight, your body fat % is now higher! Silliness :D
You're losing inches, so you're doing it right. Sometimes when you get fitter, you lose inches and not pounds, so that's ok too!
Fitness Minutes: (2,879)
590 3/29/12 4:31 P
If you are using electronic scales to measure your body fat percentage, you should be aware that they are quite sensitive to your hydration levels. They work on the principle that muscle is wet, while fat is dry - but natural changes in your hydration levels can change the reported fat and lean percentages, when in fact nothing has changed.
It does matter how you are tracking you % Body Fat. Most at home methods are not very accurate. Some college's have a department that will allow you to do underwater weighing and other accurate methods. You could call and as for the Exercise Science Department or something similar (callipers, BOD pod, ect.). There is usually a small cost but sometimes you can volunteer for the students to practice on you!
Fitness Minutes: (197,934)
3/29/12 12:29 P
The previous poster is incorrect.
BMI is a number based on height/weight ratio, body fat% is how much bodyfat (vs lean body mass) you have.
3/29/12 12:12 P
How are you determining your body fat % and lean mass? There's not really any accurate method of measuring body fat short of the calipers test or underwater weighing. BMI is a measure of body fat purely based on weight & height and nothing else; it doesn't take into account actual fat or muscle and simply places you into a category versus giving you a specific, exact percent.
Fitness Minutes: (2,879)
590 3/29/12 11:29 A
I just tracked my measurements, and printed the report. I'm highly confused on the difference between the BMI and the Body Fat %. My Body Fat % is going up, while my Lean is going down as well as my BMI. Is that normal? is it supposed to go up? It sounds like it shouldn't be? I've lost inches and weight.