BMI, the full name is Body Mass Index, Chinese for Body Mass Index, is a standard commonly used in the world to measure the degree of fat and thinness of the human body and whether it is healthy. The formula for calculating BMI is: BMI = weight (kg) height 2 (m2). The calculation formula of BMI seems simple, but it contains profound theories and applications behind it, which can not only reflect a person's nutritional status and health risks, but also guide a person's lifestyle and health management.
What is the formula for calculating BMI?What is the origin and principle of the BMI calculation formula?
The formula for calculating BMI is: BMI = weight (kg) height 2 (m2). The formula for calculating BMI was proposed in the 19th century by the Belgian mathematician, statistician and sociologist Adolphe Quetelet, who discovered that the weight of the human body is proportional to the square of the height, that is, the weight of the height 2 = constant, and this constant is the BMI.
The principle of the calculation formula of BMI is based on the geometry and proportions of the human body, assuming that the human body is a cylinder, then the body weight is the volume multiplied by the density, and the volume is the base area multiplied by the height, that is, the body weight = R2H, where R is the radius, H is the height, is the density.
If we assume that the density of the human body is constant, then the body weight is proportional to R2H, which in turn is proportional to H, i.e., R=Kh, where K is a constant. Therefore, body weight is proportional to h3, i.e. body weight = h3, where is a constant. If both sides are divided by H2 at the same time, then the weight H2 = H, i.e., BMI= H, where is a constant.
This shows that BMI is proportional to height, and the scale factor is a constant and does not vary with individual differences. This is the origin and principle of the BMI calculation formula.
What is the use of the formula for calculating BMI?What is the significance and value of the BMI calculation formula?
The BMI formula has many uses, mainly to assess whether a person is of moderate weight and whether there are health problems such as obesity or malnutrition. The significance and value of the BMI calculation formula can be understood from the following aspects:
The BMI calculation formula is a simple and universal method, it only needs to know a person's weight and height, you can quickly calculate a person's BMI, without the need for other complex measurements and instruments, and is not affected by gender, age, race and other factors, therefore, it can be widely used in different groups of people and occasions, such as medical, sports, insurance and other fields.
BMI calculation formula is a scientific and objective standard, it is based on the geometric shape and proportion of the human body, reflecting the relationship between a person's weight and height, rather than simply judging by weight or height, therefore, it can effectively avoid some subjective and one-sided misjudgments, such as judging people by appearance, fat for beauty, etc., and can also effectively distinguish different body types and physiques, such as muscle type, skeleton type, etc.
The calculation formula of BMI is a meaningful and valuable indicator, which is closely related to a person's nutritional status and health risks, because underweight or overweight will affect a person's body function and metabolic balance, increase the risk of disease and death, such as cardiovascular disease, diabetes, osteoporosis, etc., therefore, it can be used as an important basis for a person's health management and intervention, guiding the improvement and adjustment of a person's lifestyle and dietary Xi.
How is the formula for calculating BMI applied?What are the conditions and limitations of the BMI calculation formula?
How to apply the BMI calculation formula is mainly based on a person's BMI value, compared with the corresponding standard or range, to determine whether a person's weight is normal, and whether there are problems such as obesity or malnutrition. The application of the BMI calculation formula needs to pay attention to the following conditions and limitations:
The formula for calculating BMI needs to choose the appropriate standard or range, because different countries and regions may have different BMI standards or scopes to adapt to different races and environments.
For example, the criteria or ranges recommended by the World Health Organization (WHO) for BMI are:
Underweight: BMI < 185. Normal weight: 185 BMI<25, Overweight: 25 BMI<30, Obesity: BMI 30;
And the standard or range of BMI in China is: underweight: BMI<185. Normal weight: 185 BMI<24, Overweight: 24 BMI<28, Obesity: BMI 28.
Therefore, when applying the calculation formula of BMI, it is necessary to choose the appropriate BMI standard or scope according to the country and region where you are located, so as to avoid misjudgment and misleading.
The formula for calculating BMI needs to take into account the differences and particularities of individuals, because different individuals may have different body structures and compositions, as well as different physiological and pathological states, which will affect the calculation and interpretation of BMI, for example, athletes, pregnant women, the elderly, Children, etc., are not suitable to use the BMI formula to assess weight and health, because their weight-to-height ratio may be different from the general population, or their weight and height changes may not be related to health, or the relationship between their weight and height may have other factors affecting health. Therefore, when applying the calculation formula of BMI, it is necessary to consider the differences and particularities of individuals, and avoid overly simplistic and generalized conclusions and suggestions.
The BMI calculation formula needs to be combined with other indicators and methods, because the BMI calculation formula can only reflect the proportion of a person's weight and height, but not a person's body fat percentage, muscle mass, bone density and other body components and indicators, which are all important factors that affect a person's health and aesthetics, for example, a person's BMI may be within the normal range, but his body fat percentage may be too high, leading to obesity and metabolic disorders;Or a person's BMI may be above the normal range, but his muscle mass may be high, leading to health and strength. Therefore, when applying the calculation formula of BMI, it is necessary to combine other indicators and methods, such as body fat scale, skinfold thickness, waist circumference, etc., to obtain a more comprehensive and accurate assessment and recommendation.