Wednesday, March 9, 2011

Preconceived Notions

From "assumption - taking something for granted; something expected"

I made an erroneous assumption about my weight loss. I knew that BMI wasn't always the best way to choose my weight loss goal, but I didn't think it could be that far off target. My original goal was to drop to 135 pounds, which is on the high side of "normal" weight for my height. We did our reassessment today for the Time to Change program, so I was playing around with my numbers to see where I'm at for my goal.

I went to a BMI Calculator to play with numbers. My BMI is awful, but my waist-to-hip ratio is within healthy limits. After a few minutes of clicking around, I stumbled upon a Body Fat Chart that explains body fat percentage categories and how one should make sure they aren't losing weight beyond a healthy fat percentage. Here's my breakdown: I weigh 194.1 pounds currently and have a body fat percentage of around 39%.

194.1lbs x 39% = 75.699lbs fat
194.1lbs - 75.699lbs = 118.401lbs lean body mass

This means that I have about 118 pounds of stuff that I can't or shouldn't try to lose, like bones, organs, and muscle tissues. On top of this number, I need to have a healthy fat percentage. I want to be between the high end of fitness body type and the low end of acceptable body type (23-27% body fat). I used the formulas to see what my current goal looks like. It is completely unreasonable!

Current Goal = 135lbs
135lbs - 118.401lbs = 16.599lbs fat
16.599lbs / 135lbs = 12.3% fat

I played around with numbers again with my body fat percentage goal in mind, and this is what I decided would be good for me.

New Goal = 155lbs
155lbs - 118.401lbs = 36.599lbs
36.599lbs / 155lbs = 23.6% body fat

This seems perfectly reasonable to me. I'm going to change my weight loss goal to be 155 pounds. According to BMI, I'll still be "overweight," but it would be healthy in other ways. I think I'm going to scrap BMI and focus on my body fat percentage, waist circumference, and waist-to-hip ratio from now on. I'm forever astounded by the amount of research one needs to do to lose weight in a healthy way!