Ideal Body Weight: What does it mean?

woman weighing herself on scaleIdeal Body Weight: What does it mean?

Most people choose their ideal body weight (IBW) number as their long term weight loss goal. Ideal bodyweights can be found on Body Mass Index Charts (BMI), which are widely used by health professionals, allied health professionals, fitness enthusiasts, and those just looking to shed a few pounds. But, what does that IBW number mean?

History Lesson

Ideal body weight charts originated from an extremely old index (mid 1800s old) called the Broca Index. Standard body weight was determined by subtracting 100 from body length in centimeters. The BMI chart was later developed from the Broca Index. The BMI was and still is determined by dividing one’s weight by height. Scientists originally used these charts to study and compare the health of populations with respect to their weight.

Nuts and Bolts

A pattern was noticed between certain weight ranges and deaths. Low body weights seemed to correlate with tuberculosis and pneumonia which were the leading causes of death at the time. Remember, this originated in the mid 1800s. Medical professionals concluded that individuals of higher weight would fair better with respect to those common illnesses. This was critical information to have in order to possibly improve quality of life. It was especially important for those in the business of insuring a person’s life. This is why the Metropolitan Life Insurance Company and others, created height and weight tables. Today, these tables are still used to identify healthy weight individuals and individuals with weights that are “unhealthy” a.k.a. correlated to higher death rates. The ideal body weight  ranges have evolved over time due to new science concerning poor health conditions associated with higher body weights. In essence, a person’s body weight was used by medical professionals and insurance companies to gauge one’s health/insurability.

BMI Isn’t For Everyone

There are a few drawbacks to using the BMI chart of today. It’s important to note that the standard tables were based on adults between the ages of 29 and 59. So it should not apply to children. Another fine print note is that one inch should be added to your height, because the chart took into account individuals wearing one inch heeled shoes at the time. Yes. Seriously. Lastly, the lean body mass verses fat mass is not accounted when using either chart.

I would recommend that one NOT use the BMI chart if they are:

  • Adult non sedentary person (Athlete/Bodybuilder/Fitness Enthusiast…):

These individuals have more muscle on their body than fat, and because muscle by volume weighs more than fat, the BMI chart is not going to be accurate gauge. Since BMI is determined by weight and height, more muscle on the body will cause an individual to have a high BMI. Body fat percentage is a much better tool to use in this instance. (Learn Why Your Body Fat Percentage Has Nothing To Do With Your BMI)

  • Elderly:

Medical professionals encourage a slightly higher BMI for the elderly to help combat osteoporosis. The theory is that a little bit more body weight challenges bone structure, making it stronger. The elderly are also encourage to strength train for this same reason.

  • Children:

The BMI chart is not designed for children. Perhaps this is the beginning of another evolutionary period of the BMI chart to address the increasing risks of childhood obesity.

The Bottom Line

So what then does IBW mean? Generally speaking, for sedentary adult persons, it means that if you are in a healthy weight range on the chart, you are less likely to suffer from death compared to someone lighter or heavier than you.


1. Czerniawski, M. (2007). From Average To Ideal: The Evolution of the Height and Weight Table in the United States 1836-1943. Social Science History Association. DOI-10.1215/01455532-2006-023
2. The Annals of Pharmacotherapy. (2000). The origin of the “ideal” body weight equations.
3. US National Library of Medicine. (2013). Body Mass Index.
4. Broca Index.

See Also:

Author Profile: Octavia Henderson Octavia Henderson is the owner and operator of Oh! Fitness LLC, an in-home personal training company. With over 10 years experience in the health & fitness industry, she specializes in women's personal training. Octavia holds a bachelor of Science in Exercise Science from Norfolk State University. She is also a certified personal trainer through the American College of Sports Medicine, and is a certified fitness nutrition specialist with the International Sports Sciences Association. In addition to reaching aesthetic goals, her mission is to help make healthy living as easy as possible, and ultimately improving the long term health of her clients. “I understand weight management and body composition first hand, because I was my first client. As a young adult, I struggled with being overweight in part from not being active enough and eating lots of traditional southern (i.e. soul) foods. I've made poor food decisions partly out of habit and not knowing what healthy food really was or what it could be. In order to become the healthier person I am today, it took me learning how to exercise the right way, and not only finding healthy foods that taste good to me, but actually learning how to eat those foods throughout the day. That's what it takes to not only have the body, but live a healthier life. I hope to empart the knowledge from my education and personal experience so that someone else can realize their healthier self.” - O. Henderson When she isn't training clients, Octavia enjoys participating in road races, obstacle courses, and mountain biking. On rest days she enjoys lots of mind and body numbing tv, couch potato style. She can be contacted at Ovhenderson (at) OhFitnessLLC (dot) com.

Disclaimer: The views of the author are his or her own, and do not necessarily reflect the opinions of Ask The Trainer.
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