What is the body mass index (BMI)?
Body mass index (BMI) is an approximate measure of obesity.
Body mass index (BMI) is a person’s weight in kilograms divided by the square of the body’s height in meters. It indicates whether the weight is appropriate for the person’s height. Another way to calculate BMI is to multiply the person’s weight in pounds by 703 and divide it by the height (in inches) squared.
BMI is the most inexpensive screening tool to measure obesity. Although it does not directly measure body fat, it can be correlated with more direct measures of body fat.
The various categories of BMI include the following
- BMI values of less than 18.5 kg/m2 are considered underweight.
- BMI values between 18.5 kg/m2 to 24.9 kg/m2 are healthy.
- BMI values between 25 kg/m2 to 30 kg/m2 are overweight.
- BMI values greater than 40 kg/m2 are considered obese.
Example: If a person weighs 68 kg and is 165 cm (1.65 m) tall, BMI is calculated as 68 ÷ (1.65)2 = 24.98 kg/m2, which means that the person has a BMI of 24.98 and is considered to bea healthy weight.
How is BMI used?
Body mass index (BMI) is a screening tool. It does not reflect body fat or the health status of an individual. Moreover, the physician will also assess the individual’s diet, physical activity and family history to determine if BMI is a health risk.
What are the BMI trends for adults in the United States?
Since the 1970s, the prevalence of adult body mass index (BMI) above 30 kg/m2 has been increasing. Although recently, there is a decline in this trend except for older women Women over the age of 60 years old have continued to remain obese all these years.
Are there any issues with using BMI?
Healthcare professionals often use body mass index (BMI) as a screening tool to identify weight problems. Although it gives a good estimation of body fat for most of the individuals, it may be erroneous to use in the case of bodybuilders and other muscular people who have high muscle mass. High bone density may also result in high BMI. BMI may underestimate body fat in people who have lost muscle mass, especially in the older population. At the same BMI, body fatness may differ among the following populations:
- Men and women
- Blacks and whites
- Older people and younger adults
- Athletes and non-athletes
What is the ideal weight?
The ideal weight has been mentioned in the below table
HeightMinimal Risk (BMI under 25)Moderate Risk (BMI 25-29.9) OverweightHigh Risk (BMI 30 and above) Obese4'10''118 lbs or less119-142 lbs. 143 lbs. or more4'11''123 or less124-147 148 or more5'0''127 or less128-152 153 or more5'1''131 or less132-157158 or more5'2''135 or less136-163 164 or more5'3''140 or less141-168169 or more5'4''144 or less 145-173174 or more5'5''149 or less150-179 180 or more5'6''154 or less155-185186 or more5'7''158 or less159-190191 or more5'8''163 or less169-202197 or more5'9''168 or less169-202203 or more5'10''173 or less174-208209 or more5'11''178 or less179-214215 or more6'0''183 or less184-220221 or more6'1''188 or less189-226227 or more6'2''193 or less194-232233 or more6'3''199 or less200-239240 or more6'4''204 or less205-245246 or more
What are the advantages of maintaining a healthy weight?
By maintaining a healthy weight, an individual enjoys the following advantages
- Reduced risk of heart disease and certain cancers
- Better sleep quality
- Less muscle and joint pain
- Reduced risk of high blood pressure and diabetes
- Better regulation of bodily fluids
- Reduced burden on the heart and circulatory system
- Increased energy and ability to complete the desired activities
- Reduced cholesterol levels
- Reduced risk of gallbladder disease