I am frequently asked, “What is a good body fat percentage?” whenever taking measurements for a client. Body fat percentage is simply a ratio of fat to lean body mass, which includes muscle, bone, organ tissue, blood and everything else. Therefore, an individual weighing 150 pounds with 10% body fat has 15 pounds of body fat and 135 pounds of everything else. Fat is essential for certain body functions such as temperature regulation, cushioning organs and as the main storage for the body’s energy. Below is a popular chart from the American Council on Exercise that provides general guidelines for assessing acceptable body fat percentages in men and women.
Knowing your body and tracking your body fat percentage can help you manage your weight and set realistic goals for weight loss. The example below demonstrates why it is not always effective to set an arbitrary goal like “I want to lose 20 pounds.”
For this example, let’s imagine a 130 pound woman with 23% body fat who wants to lose 20 pounds.
Initial body fat: 130 pounds X .23 = 30 pounds (body fat)
Lean body mass: 130 pounds – 30 pounds = 100 pounds (lean body mass; bones, organs, blood, everything else)
Goal: 130 pounds – 20 pounds = 110 pounds (total body weight)
Losing 20 pounds in this instance places this woman at risk for an unhealthy and dangerously low body fat percentage according to the chart above.
100 pounds (lean body mass)/110 pounds (total body weight) = 9% body fat
The more realistic goal for this woman would be to reduce her body fat to 18%.
130 pounds X .18 = 23 pounds (body fat)
100 pounds (lean body mass) + 23 pounds (body fat) = 123 pounds total weight
Therefore, the goal for this woman should be to lose 7 pounds of fat to get to a healthy body fat percentage of 18% at a total weight of 123 pounds. Losing more than 7 pounds means losing lean body mass which is can be problematic.
So, before you set a weight loss goal, remember to take into account both your lean body mass and body fat percentage. Keep your weight loss goals realistic and remember to keep lean calorie burning muscle and lose just the fat.