Breaking Down Diet Culture Body Composition: What It Is and Why It Matters By Jill Corleone, RD Jill Corleone, RD Jill is a registered dietitian who's been writing about nutrition, health, and fitness for more than 20 years. Learn about our editorial process Updated on November 04, 2022 Medically reviewed Verywell Fit articles are reviewed by board-certified physicians and nutrition and exercise healthcare professionals. Medical Reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more. by Rachel Goldman, PhD, FTOS Medically reviewed by Rachel Goldman, PhD, FTOS Facebook LinkedIn Twitter Rachel Goldman, Ph.D., FTOS, is a licensed psychologist, clinical assistant professor, speaker, and wellness expert specializing in weight management and eating behaviors. Learn about our Medical Review Board Print Getty Images / GrapeImages Table of Contents View All Table of Contents What is Body Composition? What is Body Fat? Body Composition vs. BMI How to Measure Body Composition Factors to Consider Changing Your Body Composition Frequently Asked Questions Do you have a love-hate relationship with your bathroom scale? The bathroom scale may be a good tool for measuring weight, but it may not accurately reflect your true health. Body composition takes your weight measurement one step further, figuring out what percentage of your weight comes from fat, muscle, and bone. The difference between fat mass and non-fat mass (muscle and bone) paints a more complete picture of your health and fitness. This article reviews the basics of your body composition, what it means, and what you can do about it. We've tried, tested, and reviewed the best bathroom scales. If you're in the market for scale, explore which option may be best for you. What Is Body Composition? Body composition is the phrase used by medical professionals and the health community to refer to the percentage of fat, water, bone, muscle, skin, and other lean tissues that make up the body. Knowing your body composition provides more detailed information about your health. Two people can weigh the same, but have very different wellness and fitness needs because of their body composition. Why It’s Important Body composition is important because it measures your overall health and fitness level in terms of your body fat percentage. Your bathroom scale can’t tell the difference between how much of your weight comes from fat and how much from muscle. But body composition measurements can. Less fat and more muscle tends to point toward a better level of health. Body Image: What It Is and How to Improve It What Is Body Fat? Body fat includes all the stored fat in your body. There are two types of body fat: Subcutaneous fat: This is the layer of fat under your skin. It insulates and protects your body. Visceral fat: This is the fat that surrounds and cushions your abdominal organs. In addition to insulating and protecting your body, fat provides energy, carries fat-soluble vitamins, makes certain hormones, and serves as a building-block for cell membranes. You need a certain amount of body fat to perform these functions—this is known as essential fat. Body Fat Percentage Body fat percentage is the percent of fat that makes up your total body weight. Many factors influence your body fat percentage, including sex, age, fitness level, and lifestyle. The body fat percentage ranges come from the American Council on Exercise (ACE). 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 a lower body fat percentage than people who are physically fit because having less fat improves their athletic performance. However, when body fat percentages dip too low, athletic performance suffers and immune function declines. On the flip side, a body fat percentage that’s too high is a risk factor for chronic illnesses like diabetes, high blood pressure, and heart disease. An Overview of Reducing Body Fat Body Composition vs. Body Mass Index Body composition and body mass index (BMI) are tools that assess body fatness. However, the methods used to measure body composition and BMI differ. Additionally, BMI may not provide accurate results in all situations. Body Mass Index (BMI) is a dated, biased measure that doesn’t account for several factors, such as body composition, ethnicity, race, gender, and age. Despite being a flawed measure, BMI is widely used today in the medical community because it is an inexpensive and quick method for analyzing potential health status and outcomes. How to Improve Body Composition With Nutrition and Exercise Body Mass Index BMI is a tool that has been used by health professionals to assess body fatness and health. It’s a mathematical equation that compares your weight to your height. BMI = (weight in pounds)/(height squared) X 703 For example: (150 pounds)/(66 inches x 66 inches) X 703 = 24 This BMI table is from the Centers for Disease Control and Prevention (CDC). Less than 18.5 = underweight18.5 to 24.9 = healthy weight25.0 to 29.9 = overweight30 or higher = obesity You don’t need any special equipment to measure BMI, making it a quick tool to assess body fat and health. What Is Body Positivity? How to Measure Body Composition There are a number of ways to measure body composition. However, you need more than a bathroom scale and calculator to figure out what percentage of your weight comes from fat and what percentage comes from muscle. Bioelectrical Impedance Bioelectrical impedance (BIA) is a tool that estimates your body composition by measuring your body’s resistance to a low-level electric current, or impedance. Muscles have a lower resistance to an electric current than fat. Pros Painless, quick, and easy You can purchase scales with BIA technology to use at home Cons Not a good predictor of body fat percentage in all people Hydration affects results Skinfold Measurements Skinfold measurements involve the use of special calipers that measure the skinfold—subcutaneous fat—on different parts of your body. Fitness trainers use skinfold measurements to assess body fat because it’s quick and convenient. Pros You can wear shorts and a t-shirt when getting measured The test is quick and painless Cons Difficult to get accurate results when performed by someone without proper training Not a good tool for measuring body composition in people with weight challenges DEXA Scan The DEXA scan, or dual-energy X-ray absorptiometry scan, uses a low-level X-ray to measure bone, muscle, and body fat. Pros Fast and painless test Provides regional body composition Measures bone mineral density Cons Requires trained medical professionals for testing Not suitable for all body types Hydrostatic Weighing Hydrostatic weighing involves full submersion in a water tank, using water displacement to measure body composition. Since fat floats and muscle sinks, a person with more lean body mass weighs more underwater. Pros Gives the most accurate results Cons Not widely available Requires special equipment and professional testers Bod Pod Bod pod is similar to hydrostatic weighing, but uses air displacement instead of water displacement to measure body composition. For this test, you sit in an egg-shaped chamber, which uses your body weight and volume to determine your body composition. Pros Test is quick and provides a print out of your measurements, including calorie needs Results are accurate Cons Overestimates body fatness in lean individuals Clothing and facial hair may affect results Factors to Consider Body composition provides valuable information about body fat percentage. However, your body shape is unique to you and there are uncontrollable factors that affect your body composition including: Age: You lose muscle as you get older, which affects your body composition. However, age-related muscle loss is most often due to a decrease in physical activity.Genes: Your genes determine your body type and composition and your inherited body type may have more body fat that’s hard to lose.Hormones: Hormones also influence body composition. Testosterone is a male sex hormone that increases muscle mass.Sex: Due to a combination of genetics and hormones, women have more body fat than men. Changing Your Body Composition To change your body composition, you need the right balance of physical activity and nutrition to reach your goals. Slow and steady changes work best when you want to increase muscle and lose fat. It's important to remember that some factors will remain out of your control. Before making any changes to your diet or workout routine, consult with your primary care provider or a registered dietitian for guidance. Body Acceptance: What It Means and How to Achieve It A Word From Verywell Your body composition may help you better understand your current level of health and fitness. It can also serve as a measuring tool to monitor progress when starting a new fitness or wellness program. When trying to change your physique to improve your fitness level, it’s important to implement a safe and effective workout routine and a balanced eating plan. Seek advice from a health care professional before making any major changes to your diet or exercise routine. Frequently Asked Questions Which are the 3 somatotypes (body types)? The three somatotypes include ectomorphs, endomorphs, and mesomorphs. These body types are determined by your genetics. A person with an ectomorph body type has very little body fat and muscle and struggles to gain weight. Someone with an endomorph body type, on the other hand, has a high percentage of body fat and muscle and has no problems gaining weight. Mesomorphs have an athletic build and can gain and lose weight easily. What is the 4-component model of body composition? The 4-component model of body composition measures body fat, water, mineral, and protein content to assess body composition. By comparison, the traditional 2-component model only uses fat mass and fat-free mass to assess body composition.Because the 4-component model measures multiple components to assess fat mass and fat-free mass, it provides more accurate measurements for those who don’t fit the traditional body composition references.This model is often used to measure body composition in children. What is a healthy body fat percentage for males and females? According to data from the American Council on Exercise, body fat percentages for males generally range from 18% to 24% and for females 25% to 31%. Body fat percentages that measure higher than that range classify someone with obesity.If you’re an athlete or regular gym-goer, it’s possible to have a body fat percentage lower than the acceptable range for your sex and still be healthy. However, a body fat percentage less than 5% for males and 10% for females is unhealthy. 12 Sources Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. University of California at Davis. Sports Medicine. Body composition. Mittal B. Subcutaneous adipose tissue & visceral adipose tissue. Indian J Med Res. 2019;149(5):571-573. doi:10.4103/ijmr.IJMR_1910_18 American Council on Exercise. Percent body fat calculator: skinfold method. Mehta J, Thompson B, Kling JM. The female athlete triad: It takes a team. Cleve Clin J Med. 2018;85(4):313-320. doi:10.3949/ccjm.85a.16137 Centers for Disease Control and Prevention. About adult BMI. Duren DL, Sherwood RJ, Czerwinski SA, et al. Body composition methods: comparisons and interpretation. J Diabetes Sci Technol. 2008;2(6):1139-1146. doi:10.1177/193229680800200623 Holmes CJ, Racette SB. The utility of body composition assessment in nutrition and clinical practice: an overview of current methodology. Nutrients. 2021;13(8):2493. doi:10.3390/nu13082493 Wilkinson DJ, Piasecki M, Atherton PJ. The age-related loss of skeletal muscle mass and function: Measurement and physiology of muscle fibre atrophy and muscle fibre loss in humans. Ageing Res Rev. 2018;47:123-132. doi:10.1016/j.arr.2018.07.005 Schnurr TM, Gjesing AP, Sandholt CH, Jonsson A, Mahendran Y, Have CT, et al. (2016) Genetic correlation between body fat percentage and cardiorespiratory fitness suggests common genetic etiology. PLoS ONE 11(11): e0166738. doi.10.1371/journal.pone.0166738 Karastergiou K, Smith SR, Greenberg AS, Fried SK. Sex differences in human adipose tissues - the biology of pear shape. Biol Sex Differ. 2012;3(1):13.doi:10.1186/2042-6410-3-13 University of Houston. Center of Wellness Without Borders. The 3 somatotypes. Wells JC, Fuller NJ, Dewit O, Fewtrell MS, Elia M, Cole TJ. Four-component model of body composition in children: density and hydration of fat-free mass and comparison with simpler models. Am J Clin Nutr. 1999;69(5):904-912. doi:10.1093/ajcn/69.5.904 Additional Reading Kravitz L, Heyward VH. The University of New Mexico. Getting a grip on body composition. Nuttall FQ. Body mass index: obesity, BMI, and health: A Critical review. Nutr Today. 2015;50(3):117-128. doi:10.1097/NT.0000000000000092 By Jill Corleone, RD Jill is a registered dietitian who's been learning and writing about nutrition for more than 20 years. 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