BMI - Not The Greatest Indicator of Health

I went on my Instagram the other day to chat about BMI and some horror stories that had come up for clients of mine (and other health practitioners that I know)… Stories of people in larger bodies going into doctors’ offices with legitimate concerns and getting told to just lose weight and later on finding out they had severe undiagnosed issues like PCOS, hypo/hyper-thyroid, tumors, cancer, etc. Visits where unprofessional comments about weight turned into severe eating disorders. The list goes on.

It got me thinking about what a lot of physicians are using to classify patients as “overweight" and “obese” and thus in came in BMI. Right at that point, I saw a viral post that BMI was created by a Mathematician/Astronomer (Note: NOT a Physician) in the early 19th century and I had to look into it.

WHAT IS BMI?

Body Mass Index (BMI) is a calculation of your size that takes into account your height and weight.

THE HISTORY OF BMI:

The BMI was introduced in the early 19th century by a Belgian Mathematician/Astronomer (Note: Not a Physician) named Lambert Adolphe Jacques Quetelet to give a quick and easy way to measure the degree of obesity of the general population that was then used to assist the government in allocating resources. Later it was used by life insurance companies to determine ones likelihood of reaching an advanced age. It’s been recognized that during Quetelet’s time there were no calculators, computers or electronic devices – which is probably why he opted for a super-simple system.

Ok, well, there seems like there are multiple problems here…

THE ISSUES WITH BMI:

1. BMI does not measure “health” or a physiological state (such as resting blood pressure) that indicates the presence (or absence) of disease. It is simply a measure of one’s relative size. Plenty of people have a high or low BMI and are healthy and, conversely, plenty of folks with a normal BMI are unhealthy. In fact, a person with a normal BMI who smokes and has a strong family history of cardiovascular disease may have a higher risk of early cardiovascular death than someone who has a high BMI but is a physically fit non-smoker.

   • In one study, more than half of those considered overweight by BMI had a healthy “cardiometabolic profile,” including a normal blood pressure, cholesterol, and blood sugar. About a quarter of people with normal BMI measures had an unhealthy cardiometabolic profile.

2. It doesn't take into consideration the relative proportions of bone, muscle and fat in the body. But bone is denser than muscle and twice as dense as fat, so a person with strong bones, good muscle tone and low fat will have a high BMI. Thus, athletes and fit, health-conscious individuals who work out a lot tend to find themselves classified as overweight or even obese.

3. The BMI calculation is based primarily on Caucasian body types and has been shown to not be as appropriate for people of other ethnicities.

4. The BMI calculation doesn’t differentiate between men and women.

   • Women tend to have more body fat than man (for natural hormonal reasons and to allow for child bearing). Read that again, this isn't a bad thing.

5. The BMI calculation doesn’t doesn’t take into account age.

   • Elderly adults generally have less muscle and bone mass.

6. A high BMI promotes weight stigma and disinterest in physicians which threatens the individual’s health, generates health disparities, and interferes with effective medical efforts leading to more misdiagnosis due to body size.

So then what CAN we use as an indicator of health, if not the BMI?

• Lipid Levels

• Blood Pressure

• Blood Sugar

• Vitamin Levels

• Regular Recommended Screenings (i.e. Breast Exams)

• Mental Health

• Family Health History

• Exercise Habits

• Eating Habits

• Lifestyle Habits (Smoking, Drinking, Sedentary Desk Job, Etc.)

• Etc.

You know your body better than anyone else, because YOU live in it. Only YOU can intuitively tell if something feels off or not right - be your own advocate at the doctor’s office. If you think something is wrong, always push for the best care, and if you’re not receiving it, find someone else.

The BMI feels severely outdated and is an over-utilized tool to simplify something that’s not simple So, can we stop relying on BMI to give us a snapshot of overall wellness? Can we stop using “prescriptions” like "eat less and exercise more"? Start having more conversations and being curious about people’s lives?

References:

https://www.scientificamerican.com/article/is-bmi-an-accurate-way-to-measure-body-fat/

https://www.medicalnewstoday.com/articles/265215#Authorities-still-promote-BMI

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2866597/

https://medium.com/s/story/the-bias-epidemic-8f27e79bd21c

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4381543/

https://www.glamour.com/story/weight-stigma-is-keeping-patients-from-getting-the-care-they-need

https://www.cdc.gov/healthyweight/assessing/bmi/adult_bmi/index.html#Athlete

https://www.npr.org/templates/story/story.php?storyId=106268439

https://www.health.harvard.edu/blog/how-useful-is-the-body-mass-index-bmi-201603309339

If you’re looking for a safe space where you can learn how to let go of dieting for good, enjoy food without guilt, and turn exercise into something you love to do rather than something you “have” to do, submit a client application to get in contact with me! I work with clients virtually all over the world helping those who are frustrated with dieting and want to change their relationship with food and themselves.

---

Hi, I’m Azul Corajoria, an Integrative Health Coach, Personal Trainer & Yoga Instructor. I support my clients in making step-by-step changes so that they can live a healthy and balanced life. By recognizing the interdependent roles of mindset, nutrition, and movement I educate and hold my clients accountable for achieving their health goals through lifestyle and behavior adjustments with an emphasis on self-care. Together, we navigate the contradictory world of nutrition through intuitive eating, practice mindful movement, and implement small mindset and lifestyle shifts that empower them to be their best selves in the easiest way possible.