What is the normal amount of fat in women?

Female friends always feel that they are overweight and have too much fat in their bodies, so they want to lose weight so that they can have a slimmer figure. However, the specific fat content in their bodies can only be known after a fat test. Generally, they choose to check by hand weighing. This method of inspection is very effective, and the most important thing is that it is very accurate.

1. Hydrodensitometry Weighing (Underwater Weighing)

It is a method of calculating the body fat weight by measuring the body's water displacement, the density of the body's lean body mass and the density of adipose tissue, and then calculating the body fat percentage. This method has small errors and high precision, but it requires special testing space and tools, and has many operating steps. It is only suitable for laboratory testing and not suitable for public self-testing.

The principle of underwater weighing is also very simple: the specific gravity of human body fat is about 0.8 kg/L, and the average specific gravity of other tissues besides fat is about 1.0 kg/L. By weighing the weight of the human body in the air, the weight when it is fully inhaled in water, and the weight after exhaling as much as possible in water, the total weight of human body fat can be calculated through simple calculation.

2. Calipers (Anthropometry- Skinfold Measurements)

It is a method of calculating the percentage of body fat by measuring the thickness of subcutaneous fat at multiple points on the human body. This method is closely related to the human body model used in the calculation process. The data of European and American human body models cannot be used in Asia, and the Japanese model cannot calculate the Chinese data well. Because this method is easy to operate and has almost no requirements for space, it has been widely adopted by many countries in recent decades.

3. DEXA (Dual Energy X-ray Absorptiometry)

It is a method of measuring body fat content by using the principle that different body tissues (minerals, lean body, fat) have different absorption rates of X-rays. In the test, a small step distance is used to synchronously detect two low radiation sources. This method is relatively new and has high accuracy, but the test is expensive and takes a long time (10-20 minutes per person). It can only be used in advanced laboratories and cannot be performed outside of experiments.

4.NIR (Near Infrared Interactance)

It is a method of measuring body fat content by using the principle that near-infrared rays penetrate and reflect different tissues of the human body to different degrees. The test usually uses measurement of the human biceps as the main test site. Substituting the test data into an equation containing height, weight, body shape, and activity level, the percentage of body fat in the subject can be calculated. This method has been widely used outside the laboratory because the instruments required are cheap and the measurement steps are simple. However, since the pressure of the probe on the body tissue is different each time, the data measured for the same subject is often different, so the testing accuracy of this method is poor.

5. Magnetic Resonance Imaging (MRI)

It is a method based on X-rays, which uses the characteristic that human tissue cells are "excited" to different degrees under the action of a magnetic field to measure the fat content in the body. One measurement takes about 30 minutes and the measuring equipment is expensive. Although the test accuracy is high, this method is only suitable for use in advanced laboratories.

6. Total Body Electrical Conductivity (TOBEC)

It is a method of measuring lean body mass based on the principle that the human body's (non-fat) lean body is a good conductor of electrical current. Although this method has high accuracy and the test time is only 10 seconds, its application is limited to advanced laboratories due to the expensive test instrument.