Body Mass Index Body Mass Index (BMI) was first put forward by Belgian generalist kettler in the middle of19th century. A body mass index lower than 18.5 indicates light weight, and it belongs to normal weight between 18.5 and 24.9. Overweight over 25 years old, obese over 30 years old. ?
Body mass index is calculated by dividing the number of kilograms by the square of the number of meters. For example, if a person is 1.75m tall and weighs 68kg, his body mass index = 68/(1.75 *1.75) = 22.2.
Body mass index is not necessarily accurate.
Because the body mass index (BMI) does not take into account a person's fat proportion and the proportions of various body components (mainly water, protein, fat, minerals and inorganic substances), it is sometimes inaccurate and can only be used as a reference standard. Body fat percentage and body composition are more important health indicators than just considering weight. Under the following circumstances, bmi may be inaccurate in showing obesity or underweight:
1, an overweight person may not actually be obese. For example, a person who works out, because a large part of his weight is muscle, his body mass index will exceed 30. If their body fat rate is low, they don't need to lose weight. Muscular people, whose weight is significantly higher than the average person, will be wrongly judged as unhealthy obesity by body mass index.
2. Due to a large amount of accumulated water in the body, the weight of patients with edema is significantly higher than that of healthy people, which will lead to a virtual high body mass index.
3. Patients with low lean body weight (fat-free body weight) will be misjudged as healthy if they have more body fat and their body mass index can be greater than 18.5.