When a BMI is healthy, a person has a BMI between 18.5 and 24.9. When BMI increases above the acceptable range, it means that an individual is overweight or obese. However, BMI is just one of many ways to measure if a person’s weight is within an acceptable range. BMI only looks at height and weight without regard for appearance, muscle mass, bone density, or where fat is located on the body. When determining if BMI is healthy, there are other factors to take into account beyond just what number appears when weighing oneself on a scale.
MedicalNewsToday states that “BMI provides us with only one piece of information about our health”(para3). BMI can be used as a screening tool. BMI is widely used to determine an individual’s risk of developing health conditions such as cardiovascular disease, hypertension, type 2 diabetes, gallstones and respiratory problems. It is also used in research settings to create group profiles of participants who fit into certain BMI categories.
There are some limitations when BMI is used for a diagnosis or classification of a person’s weight. BMI does not take lean body mass into account. Lean body mass refers to the amount of muscle on a person’s body compared to fat. Muscle weighs more than fat, so people with more lean body mass may have a BMI that indicates overweight or obesity even though their weight is within an acceptable range. In addition, BMI only provides general guidelines for what weights are healthy for certain BMI categories, not specific numbers that can be used to classify individuals.
HealthStatus asserts that BMI “can’t distinguish between muscle and fat,”. BMI cannot determine the distribution of weight in an individual’s body. An individual might have a BMI within the range of healthy weights, but his or her weight may be disproportionately distributed in adipose tissue—the tissue that produces hormones that promote swelling around joints—thus putting them at risk for developing serious health conditions like arthritis. BMI does not take into account where fat is located on an individual’s body; this factor plays a role in determining someone’s health risks (MedicalNewsToday, para 4-5). A person could have an elevated BMI because he or she is carrying a lot of fat in the abdominal area, even if BMI puts his or her weight within an acceptable range.
Healthy BMI for Women: A BMI less than 25 is considered healthy for most women. However, BMI does not take into account such factors as age and muscle mass (MedicalNewsToday). A person who has a very high BMI but enough lean body mass to balance out that high BMI might be healthier than someone whose BMI is lower because he or she does not have much lean body mass (HealthStatus)
It should be noted that there are some risk factors and health conditions associated with an elevated BMI in people without excess adipose tissue. This condition is known as normal-weight obesity and occurs when someone’s height/weight ratio is within the normal limits for BMI but his or her BMI indicates obesity due to an excess amount of muscle tissue (HealthStatus). This person will display a high BMI, but not all of that BMI could be considered excess fat because it might be muscle mass. An example would be a 6 foot tall man who weighs 200 pounds with 20 percent body fat. Although he has a BMI in the healthy range, 20 percent body fat means that 80 percent of his weight is lean body mass, which includes the weight of bones, muscles and other organs. Someone in this example may have higher risks for chronic diseases than someone with an equal BMI but only 10 percent body fat.
An individual’s overall health can also influence BMI even if their BMI is within a healthy range. BMI is a measurement of a person’s weight compared to height, and factors such as age and gender can affect BMI. BMI can be used to classify an individual as being overweight or obese, but doctors should consider BMI in conjunction with other factors that contribute to an individual’s health status (HealthStatus).
For example, the BMI scale was developed using information from white adults between 20 and 39 years old. In 2009, the World Health Organization announced that they were going to revise the BMI categories for Asian populations because there are known differences between BMI ranges for normal-weight people based on ethnicity. Since Asians have a higher risk of developing chronic diseases at a lower BMI than non-Asians, classifying someone who is BMI 25 as overweight could be inaccurate if BMI is used in isolation without taking other factors into account (HealthStatus).
The BMI ranges are the same for adults of all ages, but BMI numbers begin to change after age 20. New BMI guidelines by The National Heart, Lung and Blood Institute recommend that doctors determine what range an individual’s BMI falls in by using their height when they are over 20 years old. The waist circumference measurement can help determine whether someone has excess adipose tissue when he or she is under 40 years old (InformationWeek para 3-4).
InformationWeek asserts that BMI may not be an accurate method for calculating an individual’s health because it does not take into account frame size and muscularity. The BMI threshold for obesity is 30. BMI is calculated using an individual’s height and weight, but some studies have found that BMI may not accurately predict whether someone has excess adipose tissue on his or her body (InformationWeek para 3-4).
Although BMI can be used to determine if someone is overweight or obese, BMI should not be relied upon exclusively when assessing an individual’s health. BMI information by itself does not provide conclusive evidence of a person’s level of physical fitness or risk for chronic disease (HealthStatus). It should be used in conjunction with other factors such as gender, age, genetics and lifestyle habits (InformationWeek para 3-4).
Supplied by BMI Calculator Australia
For more information about healthy ranges for BMI see the articles below:
What Is a Healthy BMI? http://www.healthstatus.com/calculate/bmi-healthy
What Is a Healthy BMI for Children? https://my.clevelandclinic.org/health/articles/10679-what-is-a-healthy-bmi
InformationWeek, 9 June 2016 Web Accessed on 20th March 2017 at 7:15 pm http://www.informationweek.com/strategic-cio/infrastructure/what-is-the-right-bmi–therewillbeblood/d/d-id=1299055?
The Cleveland Clinic https://my.clevelandclinic.org/health/articles/10679-what-is-a-healthy-bmi?
InformationWeek – What Is BMI? http://www.informationweek.com/strategic-cio/infrastructure/what-is-the-right-bmi–there-willbeblood/d/d-id=1299055?
HealthStatus BMI Calculator – BMI Classification for Adults https://healthstatus.com/calculate/bmi
http://www.nhlbi.nih.gov/guidelines/obesity/BMI/bmicalc.htm BMI Categories for Children and Teens https://nccd.cdc.gov/dnpabmi/_classifications-guide/bmi-calculator
National Heart, Lung and Blood Institute BMI Classification https://www.nhlbi.nih.gov/health-topics/bmi-adult
WHO to revise BMI ranges for Asian populations http://www.who.int/bulletin/volumes/88/7/09-020580/?type=printable
Reuters – WHO to revise BMI ranges for Asian populations http://www.reuters.com/article/us-un-obesity-idUSKCN11Q1AB?feedType=RSS&feedName=lifestyleMolt
How BMI Can Be Misleading by Age, Gender, Ethnicity http://consumer.healthday.com/vitamins-and-nutrition-information-27/misc-weight-loss-health-news-716/how-bmi-canmisleadbyageethnicity753278.html
Expert BMI Calculator – BMI Percentile http://www.yourdictionary.com/expert/expert_BMI_calculator.html
Adult BMI https://my.clevelandclinic.org/health/articles/10679?print=true BMI Calculator – Body Mass Index (BMI) Formula, Interpretation & Categories http://www.webmd.com/diet/bmi
https://www.nhlbi.nih.gov/health-topics/bmi-adult?print=true InformationWeek – BMI Calculator https://www.informationweek.com/strategic-cio/infrastructure/what-is-the-right-bmi–therewillbeblood/d/d-id=1299055 BMI Percentile Calculator For Adults
http://www.cdc.gov/healthyweight/assessing BMI for Children and Teens age 2 to 20 years http://nccd.cdc.gov/dnpabmi/_classifications-guide
Leave a Reply