Body Fat Percentage
Body fat percentage is typically measured with calipers, handheld calculators, or fancy equipment like a DEXA scanner. All of these methods are fairly flawed in one way or another, and typically you can figure similar results with simply looking at pictures of yourself.
If you are measuring a number for body fat, it can help you realize progress with respect to weight loss or fat loss with the following:
Pounds of body fat is found by dividing your percentage of fat by 100, then multiplying times your bodyweight.
- Example: 20% body fat for a 150 pound individual.
- 20/100 = .2
- .2 x 150 = 30
- Pounds of body fat = 30 pounds
- If this individual stays at 150 pounds, but drops to 18% body fat, the scale will obviously read the same, but that individual would have 2% less fat than previously.
- 18/100 = .18
- .18 x 150 = 27
- Pounds of fat = 27
- So without “losing any weight” the individual has dropped 3 pounds of fat (30-27) and thus has changed their body fat percentage for the better.
Body Fat Percentage vs. BMI
Let’s compare the measure of body fat percentage vs. BMI. Take those two individuals from before. The ones with the same height and weight and therefore, same BMI.
Let’s say that one of them is a professional athlete, and one works a 9-5 and is physically inactive.
Although their height and weight is the same, I’m going to guess that you’re picturing two very different looking individuals. One might have a serious amount of muscle and look fairly athletic, while the other might have a bit of a belly, look unathletic, and generally unhealthy.
Looks aside, research tells us that BMI does not have a correlational or linear relationship with health risks or all-cause mortality (1, 2, 3). In fact, it was found that individuals with a lower BMI were actually at HIGHER risk for mortality than individuals with moderate BMI (4).
This same study (4) found that when adjusted for BMI and body fat percentage, higher body fat percentage was associated with increased mortality in both men and women.
On the high end, you most likely have obesity, and on the low end, you have the concept of skinny fat, where your body weight and BMI are “healthy” but your body composition is not (an idea has been reinforced from years of emphasis on a poor tool for measuring health).