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What Is BMI And Why It Is Important

Humza Khizer

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Move Over BMI, There Are Some New Kids On The Block!

Introduction

BMI (Body Mass Index) has always been the most popular way to measure the composition of the body, pertaining to health. However, current research indicates that BMI is not the most accurate and may have serious limitations<a href="#accordion">[1]</a>. 
&nbsp;

Understanding Disadvantages Of BMI And Its Alternatives

Although BMI is an affordable, easily accessible, and quick method to screen whether a person is healthy or not. Its accuracy is limited by the fact that the index does not take certain factors into account. These include: 
&nbsp;

<ul>
	<li>
	<h5>Body Fat Percentage</h5>
	</li>
</ul>

BFP (body fat percentage) is the percentage of fat tissue in your body, in comparison to the total body mass. It is measured using skinfold callipers, and bioelectrical impedance. However, for a more accurate measurement, a DEXA Scan is used. 
&nbsp;

BMI does not account for the difference between muscle and fat. Muscle tissue is denser compared to fat, and most weightlifters, despite being physically fit, are considered fat as per the body mass index. Moreover, body fat percentage is a better assessment of health because most diseases have a correlation with body fat and not body weight. 
&nbsp;

<ul>
	<li>
	<h5>Demographics</h5>
	</li>
</ul>

When BMI was originally created the data was taken from Anglo-Saxon bodies (European population). Hence, it is not a very accurate method of health depiction due to the presence of several other races and ethnicities across the world. 
&nbsp;

Despite a low BMI score, Asians have a higher incidence of metabolic diseases<a href="#accordion">[3]</a>. Moreover, a study conducted at Stanford revealed that healthy BMI values in Black women are higher than the standard BMI range; and in Hispanic women, the healthy BMI values are lower than the standard range<a href="#accordion">[3]</a>. Moreover, in black women, a BMI value of 33 is associated with a <a href="https://merisehat.pk/disease/diabetes-type-1-and-2">risk of diabetes</a>, whereas in white women the risk is present with a BMI value of 29<a href="#accordion">[3]</a>.&nbsp; 
&nbsp;

<ul>
	<li>
	<h5>Fat Distribution</h5>
	</li>
</ul>

Fat is also an important factor for determining overall health that the BMI fails to take into account. Moreover, fat in the upper body and visceral fat is correlated to health complications. For example, cardiovascular disease is linked to lower body fat in the gluteal and thigh region.

&nbsp;

<h4>"A high BMI can add to your stress. Head on over to the <a href="https://www.merisehat.pk/page/sehat-scan/" target="_blank">sehat scan </a>and check your stress level today!"</h4>

There are multiple other alternatives to track your health which can either be used individually or together. 
&nbsp;

<ul>
	<li>
	<h5>Waist-To-Height Ratio (WHtR)</h5>
	</li>
</ul>

The waist-to-height ratio measures the ratio of waist circumference to height, instead of the overall weight to height square. Moreover, the accuracy of WHtR is higher because central weight is taken into consideration. 
&nbsp;

<ul>
	<li>
	<h5>Why Is Central Fat Important?&nbsp;</h5>
	</li>
</ul>

It is important because it accumulates around the organs in the mid-section, which has a link with heart diseases. In fact, researchers have also analyzed that WHtR is more accurate for the prediction of diseases, compared to BMI<a href="#accordion">[4]</a>.&nbsp; 
&nbsp;

<ul>
	<li>
	<h5>Measurements</h5>
	</li>
</ul>

Measurements have a relation with WHtR. It is the circumferential measurement of multiple body parts, for example, arm, legs, and waist. Many people use it for the prediction of their weight loss and weight gain.&nbsp; 
&nbsp;

<ul>
	<li>
	<h5>Resting Heart Rate</h5>
	</li>
</ul>

Resting heart rate is defined as the number of heartbeats per minute, in a resting phase. It is a good measurement of one&rsquo;s cardiovascular health. The stronger your cardiovascular health, the lower your risk of heart diseases. However, resting heart rate should not be checked first thing in the morning.&nbsp; 
&nbsp;

<ul>
	<li>
	<h5>Skinfold Callipers</h5>
	</li>
</ul>

Subcutaneous fat or fat that sits under the skin is measured using skinfold callipers. This gives an estimate of the total body fat. However, it is always better to measure five to six parts of the body for accurate results. For example, your stomach and back. Moreover, with skinfold callipers, the key to accuracy is consistency.

&nbsp;

Key Points

<ul><li>BMI is a quick and easy method of assessing a person’s health outcomes, but it has tremendous limitations.&nbsp;</li><li>BMI does not address demographics, body fat percentage, or fat distribution.&nbsp;</li><li>Therefore, alternates such as waist-to-height ratio, resting heart rate, and subcutaneous fat measurements can be used.&nbsp;</li><li>Waist circumference or even blood pressure can predict the overall risks and health condition.&nbsp;</li><li>Moreover, if anyone has concerns about their BMI or overall weight, they should consult their healthcare provider for a better understating.</li></ul>

[1] Abel, R.C., Somers, V.K., Sierra-Johnson, J., Thomas, R.J., Bailey, K.R., Collazo-Clavell, M.L. and Allison, T.G., 2008. Accuracy of body mass index to diagnose obesity in the US adult population. Int J Obes (Lond), 32(6), pp.959-966.

[2] Kurian, A.K. and Cardarelli, K.M., 2007. Racial and ethnic differences in cardiovascular disease risk factors. Ethnicity & disease, 17(1), pp.143-152.

[3] Stanford, F.C., Lee, M. and Hur, C., 2019, February. Race, ethnicity, sex, and obesity: is it time to personalize the scale?. In Mayo Clinic Proceedings (Vol. 94, No. 2, pp. 362-363). Elsevier.

[4] Ashwell, M., Gunn, P. and Gibson, S., 2012. Waist‐to‐height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors: systematic review and meta‐analysis. Obesity reviews, 13(3), pp.275-286.

Staff Writer

Body mass index (BMI) is a metric or measure that is used as a snapshot of individual health in one number. It establishes the relationship between a person&rsquo;s height and weight. In clinical terms, it is used to describe an individual&#39;s adiposity or body fat percentage. 
&nbsp;

Its usefulness stems from the fact that BMI gives a better estimate of an individual&rsquo;s body fat than just body weight alone. For example, if an individual is 5 feet tall and weighs 150 pounds, they would be considered overweight, whereas, another person who weighs 160 pounds but is 6 feet tall would not be considered overweight.

That said, BMI is not a perfect metric and it does have limitations, but its popularity in the world of medicine and nutrition is reason enough to understand it. 
&nbsp;

Understanding the Importance of BMI for your health

Lambert Adolphe Jacques Quetelet, a Belgian statistician, sociologist, astronomer, and mathematician, introduced the BMI in the 1830s. It was known as the Quetelet Index at the time, and it was inspired by Quetelet&#39;s desire to identify &quot;l&#39;homme moyen&quot; or the average man<a href="#accordion">[1]</a>.

Fast forward, in 1972, the phrase &quot;body mass index&quot; was first used by Ancel Keys in a paper titled &quot;Indices of Relative Weight and Obesity&quot; published in the Journal of Chronic Diseases<a href="#accordion">[3]</a>.&nbsp;As the health hazards associated with being overweight became evident, epidemiologists throughout the world began adopting Keys&#39; BMI approach to track disease risk factors in the general population<a href="#accordion">[3]</a>. 
&nbsp;

The need for a relative body mass index was recognized from the outset of anthropometry,&nbsp;i.e.&nbsp;it was recognized as soon as serious consideration was given to body dimensions and their biological and medical consequences<a href="#accordion">[9]</a>.&nbsp;Body weight in relation to height tells us about build or form, as well as obesity or&nbsp;being overweight.

It is also important to recognize that BMI has limited utility in assessing bodyweight health in persons of short stature and does not take into consideration variations in body types between men and women. BMI-defined obesity (BMI more than or equal to 30 kg/m2) was identified in 31% of women and 21% of men in one research of 13,601 participants, whereas body fat-defined obesity was found in 62% of women and 50% of men<a href="#accordion">[10]</a>. 
&nbsp;

BMI determines how much you should weigh according to your height.

It is calculated by dividing a person&#39;s weight in kilograms by the square of their height in meters<a href="#accordion">[4]</a>.

BMI = weight [kg] / height [m2] 
&nbsp;

An alternative method to determine BMI is to multiply weight in pounds by 703 and then divide the result by height in inches squared. This calculation is based on the SI system<a href="#accordion">[4]</a>.

BMI = weight (lbs) x 703 / height (in2) 
&nbsp;

Also, there are online BMI calculators present to make it easier and accessible. 
&nbsp;

Your BMI is one technique to determine whether you&#39;re at a healthy weight<a href="#accordion">[2][4]</a>:

<ul>
	<li>Underweight:&nbsp;A&nbsp;BMI less than 18.5&nbsp;makes&nbsp;you prone to poor health.</li>
	<li>Healthy Weight:&nbsp;Your BMI ranges from 18.5&nbsp;to&nbsp;24.9, which&nbsp;is the ideal BMI for any person.</li>
	<li>Overweight:&nbsp;A&nbsp;BMI range&nbsp;of&nbsp;25-29.9&nbsp;means that the risk of poor health is low to moderate at this stage.</li>
	<li>Obese Class I:&nbsp;A&nbsp;BMI in the range&nbsp;of&nbsp;30-34.9&nbsp;is a red flag that you are at a&nbsp;high risk of poor health.</li>
	<li>Obese Class II:&nbsp;Your BMI ranges from&nbsp;35.0-39.9, which&nbsp;indicates poor health.</li>
	<li>Obese Class III:&nbsp;Your BMI is above 40, which is considered a complex chronic disease. 
	&nbsp;</li>
</ul>

If your BMI is less than 18.5 (underweight),&nbsp;your health practitioner may prescribe certain blood assessments to check your overall health since, you are more likely to have the following conditions:

<ul>
	<li>Malnutrition</li>
	<li>Anemia</li>
	<li>Weak immune system</li>
	<li>Osteoporosis</li>
	<li>Infertility 
	&nbsp;</li>
</ul>

If your BMI is above 30 (obese),&nbsp;your healthcare provider may&nbsp;order a few&nbsp;blood evaluations, such&nbsp;as a comprehensive&nbsp;metabolic panel and lipid profile, to check your general health. 
&nbsp;

Obesity makes you prone to any cardiac disease and other conditions, including:

<ul>
	<li>Heart disease</li>
	<li>High blood pressure</li>
	<li>Diabetes type 2</li>
	<li>Gallstone</li>
	<li>Osteoarthritis</li>
	<li>Non-alcoholic fatty liver</li>
	<li>Kidney diseases</li>
	<li>Sleep apnea</li>
	<li>Depression 
	&nbsp;</li>
</ul>

Please note that you can have any of the illnesses listed above without having a high BMI. You might also have a high BMI without having any of these disorders. These disorders are greatly influenced by genetics as well as other circumstances, such as smoking cigarettes or diet or consuming alcohol. 
&nbsp;

The relationship between BMI and body fat is rather substantial, nevertheless, even if two persons have the same BMI, their amount of body fat distribution may vary. 
&nbsp;

Generally speaking,

<ul>
	<li>Women have greater body fat than males at the same BMI.</li>
	<li>The quantity of body fat at the same BMI may be more or lower depending on the racial/ethnic group.</li>
	<li>On average,&nbsp;elderly people have more body fat than younger adults&nbsp;at the same BMI.</li>
	<li>Athletes have less body fat than non-athletes at the same BMI.</li>
</ul>

BMI tends to be more accurate as a predictor of body fat in those with greater levels of BMI and body fat, specifically belly fat<a href="#accordion">[7]</a>. 
&nbsp;

If you don&#39;t fit into the &quot;normal&quot; weight range, a medical practitioner could advise making modifications to your diet and way of living. However, BMI is not always the greatest indicator of whether you should reduce weight. If you have more or less muscle than is usual, your BMI may not be an accurate indicator of your body fat. 
&nbsp;

When it comes to assessing weight types, the conventional BMI has certain drawbacks, including<a href="#accordion">[11]</a>:

<ul>
	<li>BMI does not distinguish between lean body mass (the weight of everything but fat in your body) and fat mass. As a result, a person with a high BMI (due to muscle mass) might have a very low-fat mass and vice versa.</li>
	<li>Adults assigned male at birth (AMAB) and adults assigned female at birth (AFAB) utilize the same BMI chart, despite the fact that adults AFAB often have more body fat than adults AMAB.</li>
	<li>The BMI table has not been updated to account for the growing average adult height over time. 
	 
	1. The standard BMI charts cannot be followed in populations, such as, athletes, bodybuilders, children, teenagers, pregnant women, old age people and people suffering from muscular atrophy. 
	 
	2. For only children and adolescents aged 2-18 years, the BMI calculation considers age, gender, height, and weight. 
	&nbsp;</li>
</ul>

BMI isn&#39;t the sole metric used by doctors to categorize weight kinds. Other resources include<a href="#accordion">[2]</a>:

<ul>
	<li>Measuring waist circumference.</li>
	<li>Measuring skin thickness using skin fold calipers in certain areas of your body, such as the back of your upper arms and under your shoulder blades.</li>
	<li>DEXA scan and air displacement plethysmography (ADP) are used less often. 
	&nbsp;</li>
</ul>

Conclusion

Body mass index (BMI) is a controversial health assessment measure used to quantify a person&#39;s body fat and risk of disease. BMI over the range of 30 is associated with a higher risk of chronic illness; to be more specific, it usually disturbs heart rate which potentially affects the vital organs.&nbsp;A low BMI (below than 18.5) is also associated with poor health outcomes particularly, malnutrition which can ignite anemia and poor immune system.

Nevertheless, BMI is not always an appropriate measure of body fat and is not the only factor in determining your overall health. Speak with your healthcare professional if you have any questions or concerns about your weight or your risk of acquiring certain health disorders, such as heart disease.&nbsp; 
&nbsp;

Key Takeaways

<ul>
	<li>Body mass index is a metric or measure that is used as a snapshot of individual health in one number. Its purpose is to describe the relationship between a person&rsquo;s height and weight.</li>
	<li>Its usefulness stems from the fact that it provides better estimates of an individual&rsquo;s body fat than just body weight alone. However, it is not a perfect metric and it does have limitations but its pervasiveness in the globe of medicine, nutrition and its ease of use are reasons to understand it.</li>
	<li>The need for a relative body mass index was recognized from the outset of anthropometry, that is, it was recognized as soon as serious consideration was given to body dimensions and their biological and medical consequences.</li>
	<li>It is also important to recognize that BMI has limited utility in assessing bodyweight health in persons of short stature and does not take into consideration variations in body types between men and women.</li>
	<li>The relationship between BMI and body fat is rather substantial, nevertheless, even if two persons have the same BMI, their amount of body fat distribution may vary.</li>
</ul>

[1] Problems with BMI - EndocrineWeb. Accessed December 15, 2022.

[2] BMI (body mass index): What it is & how to calculate. Cleveland Clinic. Accessed December 15, 2022.

[3] Lemond A, Lawler M, Lemond A, et al. BMI Flaws, history, and other ways to measure body weight and fat. EverydayHealth.com. Accessed December 15, 2022.

[4] Obesity: What is BMI in adults, children, and teens. Medical News Today. Accessed December 15, 2022.

[5] Body mass index (BMI): Chart, calculation, & healthy BMI ranges. WebMD. Accessed December 15, 2022.

[6] Davidson K. Is BMI an accurate predictor of health? Healthline. Published August 20, 2021. Accessed December 15, 2022.

[7] About adult BMI. Centers for Disease Control and Prevention. Published June 3, 2022. Accessed December 15, 2022.

[8] Mandal DA. What is body mass index (BMI)? News. Published February 27, 2019. Accessed December 15, 2022.

[9] Ancel Keys, Flaminio Fidanza, Martti J Karvonen, Noburu Kimura, Henry L Taylor, Indices of relative weight and obesity, International Journal of Epidemiology, Volume 43, Issue 3, June 2014, Pages 655–665,

[10] Zierle-Ghosh A, Jan A. Physiology, Body Mass Index. [Updated 2022 Sep 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-.