PT on the Net Research

Body Fat Loss Formula


I've read that losing one to two pounds a week is a safe and often realistic goal for weight loss. However, I often have clients asking me what is a realistic percentage of body fat to lose in, say, one month? Or what can they expect to see in inches lost around hips and waistline in one month? I understand everyone loses differently and at different rates, but what is the average?


It takes at least eight to 12 weeks to see any changes in body fat percentage. One has to keep in mind that there is a three to four percent technique error regardless if you use the underweight or skin caliper technique. So, if re-assessing the client, he or she needs to be over that four percent error in order for the measurement to be accurate. Probably the best way to establish goals would be to estimate the client's body weight based on the ideal body fat. Refer to the formula below:

Ideal Body Weight: Lean body mass / 1 - (% body fat)

For example:

So, based on the information above, we know her ideal body fat should be around 20 to 22 percent. As a trainer, you can establish body weight goals for every four percent of body fat loss (taking into account the technique error of three to four percent).

This way you can show your client more realistic goals. Another way to look at body fat loss is that it takes about 3500kcals to lose one pound of fat.

Good luck!