The field of medicine is proud of its progress and innovations, and yet it uses a more than 150-year-old medical calculation to estimate a healthy body weight.
Has the body mass index (BMI) outgrown its value in determining the health and associated risk factors of an individual or community?
Health officials and academics agree that it is not a perfect system for measuring a person’s health, but many say it still has value after so long.
“It’s a tool that can open the door to look at some other risk factors and talk to patients about things like whether you’re getting enough sleep, what your stress is, what your eating patterns are, and you’re starting to dig more than looking at height and weight.” said Rebecca Mason, clinical nutrition manager for Spectrum Health at Grand Rapids.
“You can’t find everything about someone’s health just based on their BMI. There may be a number of other factors that affect this. It’s just a measure to start and understand where some of the risks lie, because we know that some things are related to that. “
BMI is calculated by dividing a person’s weight in kilograms by the square of his height in meters. For adults, a body mass index below 18.5 is considered too low, while an index of 25 or more indicates that a person is obese. A BMI of 30 or more is considered obese, according to the U.S. Centers for Disease Control and Prevention.
When BMI was first used in the mid-1800s, it allowed physicians to link certain health risks to body weight before developing tools used to more closely measure body fat. Obesity and high body fat are known to correlate with diseases and health conditions such as diabetes, hypertension, heart disease, liver disease, osteoarthritis, stroke and certain cancers.
Obesity is also associated with impaired immune function and decreased lung capacity, which could explain why health officials have observed worse outcomes than COVID-19 in overweight patients and / or have additional health factors.
Connected: ‘We were not a healthy population entering this;’ How COVID shed light on the weight problem in Michigan
Of the more than 900,000 adults hospitalized with COVID-19 from the start of the pandemic to November 18, 2020, about 30% were considered obese, according to the CDC. Federal officials said obesity could triple the risk of hospitalization due to COVID.
Anecdotally, doctors in Michigan also noticed trends in hospitalized patients with overweight COVID.
Clinicians often collect information about the height and weight of their patients, and their drawing tools usually automatically calculate BMI. But Mason said it is up to the individual doctor to keep an open mind and gather more information about the lifestyle when assessing the patient’s health and potential risk factors.
“It is important to ensure that doctors or health professionals try to see the whole person, and not just one small point of data,” she said.
BMI that is above or below what is considered a healthy range should not be a diagnosis in itself. But before that, start a conversation to assess someone’s sleep patterns, eating habits, mobility and stress levels.
“BMI is a useful tool for most people,” said Jim Pivarnik, a professor of kinesiology at Michigan State University who has studied body composition and body response to exercise for decades. “It’s not perfect, but is it useful?” Yes.
“You will be more right than wrong when you assess someone’s BMI obesity than nothing. Now, if you can measure the percentage of fat, is that better? Absolutely. ”
Connected: Michigan man loses 100 pounds and gets diabetes after “poor” fight with COVID
I have considered, BMI can be imperfect, especially on an individual basis.
Take, for example, athletes and other people with lean muscle mass. Their body fat percentage may be in a healthy range, but their BMI suggests they have an unhealthy weight for their height because muscle mass, body fat percentage, and even bone density are not taken into account.
That concept led Pivarnik to study the BMI of athletes and non-athletes in 2007 to determine exactly how much BMI can measure an individual’s body fat percentage. The study, published in the Journal of the American College of Sports Medicine, estimated body fat and BMI in 400 people and found that BMI did not give an accurate picture.
“(BMI) is not very useful at all when it comes to athletes,” said Pivarnik. “We clearly know that some people have a BMI that could make them look obese or obese, but obviously not.
In recent years, there has been more research on differences in body composition between different races and ethnic groups, too, which obscures the value and disadvantages of using BMI in different populations.
For example, black men and women generally have lower percentages of body fat and greater muscle mass compared to whites and Latinos. With that understanding, it is more likely that the black population will be mislabeled overweight.
Similarly, Mason said, the Asian population may have health risks that start with a lower BMI than other groups. One study found that Asian individuals have an average body fat percentage of 3% to 5% higher than whites with the same BMI.
“One of my favorite things about medicine is that it’s constantly evolving and growing, and the things we knew 100 years ago are sometimes changing and changing,” Mason said. “One thing we notice trends in is that there are certain ethnic groups where BMI gives you a different picture in some way.
After noticing shortcomings in the use of BMI to measure an individual’s health, Pivarnik said the data was probably more useful for analyzing population health and trends. He pointed to the CDC’s annual system for monitoring behavioral risk factors, which randomly surveys individuals in all 50 states by telephone.
In 2020, research showed that Michigan ranked 35th among states in the United States in terms of adult obesity. Michigan’s obesity rate of 35.2% exceeded the national average of 32.2%.
In Michigan, only four counties reported adult obesity rates that were below or below the national average in 2019, according to CDC data released last year. Among them are Vashtenav (29.4%), Oakland (30.7%), Leelanau (31.8%) and Ottawa (31.9%).
This means that 79 districts were above that threshold, including 33 with a rate of 38% or more. Among the most obese counties were Saginav (41.7%), Clare (41.6%), Montcalm (40.8%), Hillsdale (40.8%), Isabella (40.7%), Gratiot (40.6 %) and Baraga (40.5%).
Below is a map of 83 Michigan counties based on estimated adult obesity rates. Move the cursor over the county to see its rate based on the latest CDC data.
Don’t see the map? Click here.
Michigan has exceeded the national average for at least 30 consecutive years, beginning in 1990. During that period, Michigan’s obesity rate rose steadily from 14.1% in 1990, to 22.4% in 2000, and 31.7% in 2010.
Below is an American map of adult obesity rates by country, based on data from the CDC’s Behavioral Risk Monitoring System. Hover over each state to see its adult obesity rate and ranking in the state.
Don’t see the map? Click here.
Read more on MLive:
Residents in 22 Michigan counties should disguise themselves as COVID-19 numbers grow, hospitalizations rise
Children from 5 to 11 can now receive the COVID-19 amplifier
In 8 counties in northern Michigan, the cases have doubled: data on the COVID virus in Michigan for Thursday, 19.
GOP governor candidate boycotts debate, citing COVID’s “extremist” policies