While Body Mass Index (BMI) is the traditional method for assessing health through weight, it can be unreliable because it doesn’t take into account body type or composition. A less used but more reliable method is Body Fat Percentage (BF%). It measures what percent of your body is composed of fat. It does not take into account other factors such as muscle mass, bone density and lifestyle choices. As we age our BF% increases as muscle mass decreases.
Essential Fat: This is the minimum percentage required for basic functioning and survival. We need a certain amount of fat for our bodies to function. We need it for insulation as well as protection of internal organs. For women this is thought to be around 10-13% and men it is around 2-5%. This is often what bodybuilders will aim for on competition day. This range is very risky, unsustainable and not recommended for a healthy lifestyle.
Athletes: Women between 14-20% and men between 6-13% will fall into this category. This level is really only healthy if you have a higher amount of muscle mass (such as competitive athletes). This range is especially questionable for women, since some women will stop menstruating at these levels.
Fitness: This is considered the ideal range for fitness. Women fall into this category from 21-24% and men from 14-17%. This does not mean everyone in this category is actually fit or that people above this are not. This is generally the optimal range, but other factors need to be taken into account.
Acceptable: A BF of 25-31% for women and 18-24% for men is considered acceptable. This is what most people in the United States would consider a normal healthy weight. Many people who eat a healthy diet and exercise regularly will fall into this category.
Obese: A BF of 32%+ in women and 25%+ in men is considered obese. People in this range are at increased risk for chronic diseases. Most American adults would fall into this category.
*Keep in mind this is different than obese according to BMI. The obesity rate according to these standards would be higher than BMI standards.
How to Determine Your Body Fat Percentage
- Skin Fold Caliper: These cost around $5 and are a reliable way for measurement if done properly. You pinch your skin and pull the fat away from the muscle. Learning how to do this properly may take some practice, but is very useful if you learn how to do it right. You can calculate your skin fold measurements here.
- Tape Measure: You can take measurements of yourself then input them into an online calculator. This isn’t the most reliable method, but it is quick and easy. One of the major factors that could come into play is your body shape (also measuring inaccurately/ not quite in the right place).
- Bioelectric Impedance Analysis (BIA): This measures the electrical current in your body combined with your height and weight. It makes an estimation of your BF% based on this. This is not the most accurate method because hydration can impact the result, but you can do it at home and it may feel less awkward than using a skin fold caliper. If you use this method, make sure you measure at a consistent time to keep the hydration levels similar (first thing in the morning is a good bet).
- Hydrostatic Weighing: This has a high degree of accuracy for measuring BF%. It also requires going out of your way to pay $100+ to get dunked in a tank of water. For most people, this isn’t a very practical option.
- DEXA Scan: This is considered the best measurement. It includes other factors in addition to BF%. However, it costs about $250 so it is only worth it if getting a precise reading is important to you.
- The Mirror Method: If you are able to look at yourself objectively, you will probably be able to make a decent estimation of your BF% in the mirror. If you only care about being in a healthy range and liking the way you look, then this is probably a good option for you. This is especially the case if like me, you have a tendency to obsess when numbers get involved. You can do this by comparing yourself to various visual guides and the characteristics described of each range (links below). That said, looking at ourselves objectively isn’t always easy. I recommend combining this with at least one of the other methods.
There is a good chance that the gym you belong to offers body fat measurements. This may be a cost effective way to be assessed by an expert (or at least someone who knows what they are doing). Some gyms may offer this with an overall fitness assessment.
Body fat percentage is especially useful in tracking progress when you are at or around a healthy weight. You can track this along with progress in performance. Body fat percentage may be more difficult to accurately measure without a professional if you are significantly overweight, since there are less noticeable changes in definition.
When it comes down to it, the ideal BF% (once you are in a healthy range) is more a matter of personal preference. While you can be relatively healthy while overweight, the BMI and BF% guidelines were set as they are for a reason. Most women will probably want to aim between 20-25% and men between 15-20%.
Strength training plays an important role in finding a good balance. This is especially the case if you are losing weight, since you want to make sure what is lost is actually fat. Muscle is also denser and burns more calories than fat, so increasing muscle mass will give your metabolism a nice boost. Not to mention, it makes you look toned and being physically strong feels kind of bad ass.
Body Fat Pictures and Percentages (highly recommend)
Body Fat Pictures of Men & Women (highly recommend)