Body fat can be measured by calculating body mass index:
(1) Body mass index = weight (kg)/height (m) squared.
(2) Body fat rate: 1.2× body mass index +0.23× age -5.4- 10.8× sex (male 1, female 0).
Total weight is equal to lean body mass (LBM) and body fat (BF), and body fat rate is the ratio of body fat to total weight. The body fat rate of normal adults is 15%~ 18% for men and 25%~28% for women. The body fat rate should be kept within the normal range.
If the body fat rate is too high and the weight exceeds 20% of the normal value, it can be regarded as obesity. Obesity means lack of exercise, overnutrition or some diseases of endocrine system, which are often complicated with hypertension, hyperlipidemia, arteriosclerosis, coronary heart disease, diabetes, cholecystitis and other diseases;
If the body fat rate is too low, which is lower than the safe lower limit of body fat content, that is, 5% for men and 13%~ 15% for women, it may cause dysfunction.
Extended data:
Other measurement methods:
1, DEXA scanning: similar to whole-body x-ray measurement, it is recognized as the most accurate method at present. It is usually necessary to go to a professional hospital or institution for measurement. I don't know where it is in China.
2. Underwater measurement method: empty the lungs, enter the water, calculate the body density through the discharged water, and then calculate the body fat rate.
3.Bod pot: put a person in a secret room, measure the body density by the amount of air discharged, and calculate the body fat rate.
4. Body fat clip: Calculate the body fat rate by measuring the thickness of the clip fat.
5. Body fat scale, hand-held body fat meter and body composition tester: The body resistivity is measured by hand-held sensors, and then the body fat rate is deduced. ?
6. Soft ruler measurement: measure girth, and then calculate body fat rate.
No matter which method you use, you should try to use the same tool to avoid machine errors, and try to measure at the same time every day-for example, every morning on an empty stomach, when you don't drink water, take a bath, exercise or eat, it is also the best time to measure.
Generally speaking, it will be more accurate, especially when you use the body fat or body composition tester commonly used in the gym to measure, you should pay more attention to the influence of diet, exercise and bathing.
After dinner?
Because the body fat rate is inferred by resistivity, a large amount of food and blood enter the stomach after eating, forming a thick stomach wall, which is likely to be regarded as a high resistance area, thus judging body fat.
After exercise?
When measured immediately after training, blood tends to be more concentrated in the training site, which may be judged as an increase in water and muscle mass, but it is not. The magic of local instantaneous muscle gain, no matter which personal trainer you invite, you can't understand it.
After the shower?
Taking a bath, especially taking a hot bath, will increase blood circulation and allow more water to be distributed to the skin under the condition of constant body temperature, leading to overestimation of muscle mass and water and underestimation of body fat. The more consistent the conditions, the more valuable the measured data will be.
Phoenix Net-Measuring Body Fat Rate