Basics Body Composition and Body Fat Percentage Definition, Guidelines and Measurement Methods By Jennifer R. Scott | Reviewed by Richard N. Fogoros, MD Updated November 29, 2018 Pin Flip Email Print Comstock/Stockbyte/Getty Images More in Weight Loss Basics Procedures Nutrition for Weight Loss Exercise for Weight Loss Diet Plans Medications Pills and Supplements Body composition is the proportion of fat and fat-free mass in your body. A healthy body composition is one that includes a lower percentage of body fat and a higher percentage of fat-free mass, which includes muscle, bones, and organs. Body composition is measured to assess your health and fitness level. Often, you will have body composition measured at the start of a weight loss or fitness program and checked periodically to monitor your progress. What Is Body Composition? Your body is composed of two types of mass: body fat and fat-free mass. Body fat can be found in muscle tissue, under the skin (subcutaneous fat), or around organs (visceral fat). Some fat is necessary for overall health. It is called essential fat and it helps protect internal organs, stores fuel for energy, and regulates important body hormones. But you may also have excess storage of fat and non-essential body fat.Fat-free mass includes bone, water, muscle, organs, and tissues. It may also be called lean tissue. These tissues are metabolically active, burning calories for energy, while body fat is not. Body fat percent is a measurement of body composition telling how much of the weight of your body is fat. The percentage of your body that is not fat is fat-free mass. There are normal ranges for body fat, which differ for men and women. Weighing yourself on a regular bathroom scale does not truly assess your body composition because a regular scale cannot tell how much of your total weight is comprised of water, fat, or muscle. To know if your body composition is healthy, you should get an estimate of your body fat percentage. You can do so by taking simple measurements and entering them into a body fat percentage calculator. Healthy Body Composition The American Council on Exercise (ACE) gives these ranges of values for different populations: ACE Body Fat Percent Norms for Men and Women Description Women Men Essential Fat 10% to 13% 2% to 5% Athletes 14% to 20% 6% to 13% Fitness 21% to 24% 14% to 17% Acceptable 25% to 31% 18% to 24% Obese over 32% over 25% Athletes tend to have lower body fat, which may be beneficial for performance in sports such as running and cycling. But having an extremely low body fat percent is a health problem. The female athlete triad increases the risk of injury and health issues. It includes eating disorders, amenorrhea, and decreased bone mass with an increased risk of stress fractures and osteoporosis. If you are overweight or obese, you have an excessive amount of body fat and a high body fat percentage. You can improve your body composition by gaining lean body mass through building muscle and bones, and through losing excess body fat. How to Measure Your Body Composition There are several ways to get an estimate of your body fat percentage at home, at the gym, or from your doctor: Bioelectrical Impedance Bioelectrical impedance is the method used by handheld units and by BIA body fat scales you step onto like a regular scale. A small electrical current passes through your body. Fat, water and lean tissue impede the current difference to give the reading. Many scales are sold for home use and no special training is required. Some scales, like the Fitbit Aria 2, even sync with your fitness tracker so that you can see how changes to your daily activity and diet affect your weight. Skinfold Measurements Taking skinfold measurements is a method is often used by fitness trainers or as part of a weight loss program. Calipers are used to take measurements at different parts of your body. DEXA Scan A DEXA scan, or dual energy x-ray absorptiometry scan is performed in a medical setting and can also be used to check for bone density. Hydrostatic Weighing Hydrostatic weighing is a method that requires you to be fully submerged in water. It's harder to find this gold standard for body fat measurement that involves being dunked in a water tank. Factors Affecting Body Composition Your body composition can be influenced by factors you can't control: Age: People lose muscle mass as they age if they don't maintain it with sufficient weight training. This results in a slower metabolism. Sex: Women have more body fat than men as nature's way of preparing for pregnancy and nursing.Genes: These play a role in whether you are naturally lean or have a tendency to retain fat, including where you store it.Hormones: These can influence water retention and body composition. Should You Change Your Body Composition? If your body fat percent is too high, you may want to try to decrease it to improve your health, athletic performance, and wellbeing. You may also be able to decrease your risk of disease. If your body fat percent is below the level of essential fat, you may also want to make changes to bring it up to that level as that will reduce your health risks. To change your body composition for better health and fitness, aim to increase muscle mass and decrease excess fat mass. You can change your diet, start an exercise program, or combine both methods . A Word From Verywell Your body composition and body fat are important measurements when you are on a weight loss program. You could be successful in losing fat and gaining muscle without seeing your weight go down. Tracking your weight loss and fitness efforts with body composition measurement is a good way to see your progress. It is easier than ever with the wide availability of body fat scales. Was this page helpful? Thanks for your feedback! Get nutrition tips and advice to make healthy eating easier. Email Address Sign Up There was an error. Please try again. Thank you, , for signing up. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources American Academy of Orthopaedic Surgeons. Female Athlete Triad: Problems Caused by Extreme Exercise and Dieting. http://orthoinfo.aaos.org/topic.cfm?topic=A00342. American Council on Exercise. Tools and Calculators. https://www.acefitness.org/acefit/healthy_living_tools_content.aspx?id=2 Fahey TD. Fit & Well: Core Concepts and Labs in Physical Fitness and Wellness. New York: McGraw-Hill Education; 2017. National Heart, Lung, and Blood Institute. Assessing Your Weight and Health Risk. https://www.nhlbi.nih.gov/health/educational/lose_wt/risk.htm. Continue Reading Article The Differences Between Fat and Fat-Free Body Mass List Body Fat Monitors to Buy So You Can Measure Your Fitness Better Article Know How to Measure Your BMI to Determine Weight Range Article What Is Bioelectrical Impedance Analysis (BIA)? Article Fat Metabolism and Losing Weight Article How You Can Reduce Non-Essential or Excess Body Fat Article The 4 Best Ways to Track Your Weight Loss Progress Article Does You Know Why Your Body Is Changing Shape as You Get Older? Article What Should You Weigh Based on Your Height? Article The Healthiest Way to Lose Weight for Men Over 40 Article The Truth About Body Wraps and Weight Loss Article Losing Inches but Not Weight? Article How to Pick the Best Bathroom Scale for Weight Loss Article What Are the Different Types of Fat? 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