Unlike body weight -- which just takes into account the number on the scale -- your body composition takes into account where your weight comes from. Knowing what percentage of your body weight is fat offers more insight into your health, since carrying too much fat tissue affects your health, even if your actual weight falls into a healthy range. Being overfat -- whether you're also overweight or have a healthy weight but a high body-fat percentage -- poses a major health risk, so maintaining a healthy body composition lowers the risk of certain obesity-related diseases.
Better Weight Control and Metabolism
You'll have an easier time maintaining your weight and avoiding that all-too-familiar weight creep as you age if you maintain a healthy body composition. Having a healthy body composition means having a relatively low level of body fat, with most of your weight coming from lean mass, including muscle tissue. That lean tissue burns more calories 24 hours a day -- even when you're sleeping -- and accounts for about 20 percent of your daily calorie burn, compared to around 5 percent for your fatty tissue. That means a person with more muscle will have a higher metabolism than someone of the same weight, height, gender and age who has a higher body-fat percentage.
Lower Risk of Cardiovascular Disease
Having a healthy body composition can help lower your chances of developing cardiovascular disease. High body fat levels up your risk of hypertension, which is chronically elevated blood pressure. Over time, hypertension strains your heart and puts extra pressure on your arteries, which can cause heart failure. Carrying extra weight in your midsection also typically means you have visceral fat, which threatens your heart health. This deep-abdominal fat negatively affects your cholesterol levels, which in turn increases your risk of heart disease.
Reduced Risk of Other Health Conditions
Being overfat also contributes to other chronic illnesses, so maintaining a healthy body composition can lower your disease risk. Harmful belly fat increases chronic inflammation, which can make you more likely to develop inflammation-related diseases like asthma, explains Harvard Medical School. High belly fat levels also up your risk of colorectal and breast cancers, and they negatively affect your brain, boosting your risk of dementia.
Achieving a Healthy Body Composition
A definition of a healthy body composition changes according to your gender and age. For example, women in their 20s should aim for a body fat percentage of 16 to 24 percent, while men in their 20s should have lower body fat levels -- 7 to 17 percent, according to guidelines developed by the American College of Sports Medicine.
As you age, it's normal for your body fat to increase a little -- a woman in her 50s, for example, should try to maintain a body fat level of 22 to 31 percent. It can be hard to get an accurate body fat measurement at home, but your doctor or an expert at a sports clinic can help you determine your body composition. Keep in mind that you can have an unhealthy body composition even if you have a healthy weight -- a condition sometimes called "skinny fat," or normal-weight obesity -- so you could still face a higher disease risk even if you're not overweight. While you can have normal-weight obesity at any age, you'll face a higher risk of it as you get older, due to your body's natural tendency to lose muscle and gain fat.
If you're currently above your ideal body fat percentage, start cutting calories from your diet, and eat 500 fewer calories than you need each day to maintain your weight. Pair your healthy diet -- made up of nutritious, unprocessed foods, including lots of lean protein -- with strength training, which will help you retain muscle tissue and improve your body composition as you lose weight.
Remember -- when it comes to health, every little bit counts, and even a modest weight loss of 5 to 10 percent of your body weight significantly lowers your obesity-related disease risk. If you're not sure where to begin, consult nutrition and fitness professionals for help with your diet and exercise regimens.
- Health & Wellness: Body Fat Percentage
- Honolulu Star Bulletin: 'Skinny Fat' Label Shows the Vagaries of Obesity
- University of New Mexico: Controversies in Metabolism
- Harvard Medical School: Taking Aim at Belly Fat
- National Heart, Lung and Blood Institute: Aim for a Healthy Weight - Facts About Healthy Weight