Yesterday, while I was discussing my belief that body fat percentage remains my priority, I started to think about what my goal body fat percentage is. How much body fat should a grown up, athletic woman like myself shoot for? I searched the internet and found many different charts. This is the one that seems to be reasonable to me, and is based on gender/age and whether or not you want to be “average” or more lean.
I was trying to work backward and find out how to calculate how much weight I would need to lose, given maintaining my current lean muscle mass, and was a bit surprised. However, I’m not sure that the number I have for myself includes bones and other lean tissue. But, based on that and my goal body fat content of somewhere around 24, I might need to lose an additional 10 pounds. That being said, I’m doing NO exercise right now until I have the ol’ knee surgery. I build muscle very easily, so I have a feeling my goal weight will be dead on when I regain some muscle.
Here’s how you calculate, according to Marc Perry at http://www.BuiltLean.com.
To find your lean muscle mass: Take your body weight right now and multiply it by the body fat percentage your scale shows (or your trainer has given you). Now, subtract that number from your current body weight.
Say you weigh 200 pounds. Your body fat percentage is 45%. (200 X .45 = 90) Then, take your body weight (200 – 90 = 110). You have 110 pounds of lean body mass! Great, now what? How do you figure out your goal weight?
So, say you think your goal body fat percentage should be 29%, which is average for a 26-30 year old woman. You first will subtract your desired body fat percentage from 1. (1-.29=.71) Now, divide your lean body mass (in pounds) by the .71. (110/.71= 154) So, if your muscle mass (or lean body mass) remains the same, your goal weight is 154. At that weight you should be at a body fat percentage of 29%. Isn’t that cool?
Marc has the formulas all spelled out on his site.
To me, body fat percentage is what it’s about. BMI is total horse dinky. It does NOT take into account your lean mass. If they went strictly by BMI, athletes like Lance Armstrong would be obese. Remember the whole muscle weighs more than fat thing?
I hope this helps you guys like it helps me focus. It’s not the pounds as much as the lean pounds to fat pound ratio that I’m truly concerned with… well, until that scale doesn’t move. THEN, I must remember to revisit this post and adjust my thinking from somthing less emotional to something a little more cerebral.
OR the other option is to go have an iDXA scan, which I did last year. Oh, the humiliation! However, I posted my scanned image which I think is fascinating and would be totally awesome if I didn’t know who that was in the picture. I do plan to do another scan at the end of this year come hell or high water. I want to see the difference!