If you want to lose weight and maintain good health, it’s beneficial to understand why body fat is an important factor for weight loss and health. See also Body Fat Calculators
Body Weight and Body Fat
Body weight may be divided into three types: bones, muscle and fat. In a healthy female of average weight, bones make up 12 percent of total body weight, muscle/lean tissue about 35 percent and body fat about 27 percent. The remaining body weight is skin, connective tissue, tendons, blood, organs and so forth.
Body Fat is Lighter Than Muscle by Volume
Fat is lighter by volume than lean body tissue. For example, a ‘cup’ of fat is lighter than a ‘cup’ of muscle. This explains why increased physical exercise (which builds muscle) may actually cause weight gain rather than weight loss – at least to begin with.
Body Fat Requires Fewer Calories Than Muscle
Fat is metabolically less active than muscle. Meaning, it needs less calories to sustain it, than muscle. This is why body fat percentage is so important for weight control. The higher your percentage of fat (and the smaller your percentage of muscle) the less calories you need to maintain your weight and therefore the easier it is to gain weight.
Body Fat Percentage
Body fat is often expressed as our “Body Fat Percentage” or “Body Fat Percent.” Body fat percentage is the amount of body-fat-tissue as a percentage of total body weight. If your total body weight is 160 pounds and you have 32 pounds of fat, your body fat percentage is 20 percent.
Body Fat Calculation and Health
The higher your percentage of fat above average levels, the higher your health risk for weight-related illness, like heart disease, high blood pressure, gallstones, type 2 diabetes, osteoarthritis, and certain cancers.
Body Fat Location, Abdominal Fat and Body Fat Percentage
As we can see, the total amount of body fat we have is an important factor in weight control. But where our fat is stored is also important – especially for health. In simple terms, the more fat we have around our middle (abdominal fat, or visceral fat) the worse for our health. Excess abdominal fat has a strong link to “syndrome X,” the deadly quartet of high insulin, high sugar, high cholesterol, and high blood pressure. Even in people who don’t have all these problems, excess abdominal fat is associated with high levels of LDL (“bad”) cholesterol and low levels of HDL (“good”) cholesterol. All in all, abdominal fat is strongly linked to an increased risk of heart disease and stroke and is far more hazardous to health than lower-body fat.
Who Develops Excess Abdominal Fat?
Generally, men tend to store fat around their middle (apple body shape), while women store fat around their pelvis, thighs and butt (pear body shape). But while gender is the most powerful influence on the distribution of body fat, it’s not the only factor – genes and genetics also count. A 1996 study of twins found that hereditary factors are responsible for up to 70 percent of an individual’s tendency to accumulate extra weight in the midsection. Age, too, has an effect. Aging is actually responsible for the middle-age spread so common in America. But the effect of age is magnified enormously by the final factor, lack of exercise. A recent study of 427 healthy men between 17 and 90 found that in each decade of adult life, the body fat of sedentary men increased 17 percent and the waist circumference 2 percent; regular exercise, though, reduced fat accumulation to just 3 percent per decade and held the mid-body bulge to just 1 percent per decade.
For a concise explanation of how ALL surplus calories (from fats, protein AND carbs) are converted to body fat and stored as adipose tissue, see How We Gain Body Fat?
Waist Circumference – Indicator of Body Fat Location
A high waist circumference is associated with an increased risk for type 2 diabetes, dyslipidemia, hypertension, and cardiovascular disease CVD in patients with a body mass index (BMI) between 25-34.9. Furthermore, in obese patients with metabolic complications, changes in waist circumference are useful predictors of changes in CVD risk factors.
Unhealthy Waist Circumference
If you are overweight (BMI 25+), then as a very general rule, an unhealthy waist circumference is above 35 inches (women), or above 40 inches (men).