Myth 4 – The BMI Causes People to Feel Bad About Themselves

There are a couple of issues here. First of all, I don’t think the use of the BMI has caused people to have a poor self-image. If they do feel poorly about themselves, I believe it is the result of the many other instances of discrimination that they are subjected to every day. This discrimination is unfair but it is there. I truly believe everyone should feel good about their self-image no matter what it is or others may think. If someone has a BMI that suggests they are overweight or obese, no one should view that as a criticism of their character or worth as a person, but as a risk factor that they should recognize and, if motivated, work on improving. If they are aware of the truth about the health risk, and they choose to not address it, that does not diminish them. It is their health decision.

Insights For Health Bottom Line: No one should define their self-worth by a number. But you and your doctor should consider BMI, waist circumference and percentage body fat along with your family history to determine the best path to maximize your health.

I hope these last few posts gave you a clearer perspective on the value of the BMI.

For Your Health – Dr. Bob

Myth 3 – Some People Normally Have a Higher BMI & They Are Healthy

The thinking here is that a high BMI poses no health risk for some people. Since genetics plays a huge role in determining a lot of things including our metabolism, it’s probably true that some people are predisposed to have a higher BMI, but that doesn’t make it less of a risk factor. Your risk for illnesses comes from an interplay of many risk factors. So someone may have favorable risks because they are genetically predisposed to having lower blood pressure and cholesterol, but they have a family tendency of being overweight or obese. Compared to someone with high blood pressure and high cholesterol who is also overweight, they will have a lower risk of heart disease. However, if they lower their BMI, they will have an even lower risk.

I need to work on my lifestyle through making healthier food choices and exercising regularly to counteract these risk factors. The same goes for someone who has a tendency to have a high BMI. They have to work harder than someone whose genetics have a higher metabolism.

Insights For Health Bottom Line: Though favorable genetics as shown in your family’s health history may lessen the impact of a high BMI, your risks will be even lower if you maintain a more normal BMI.

Myth 2 – The BMI Doesn’t Really Mean Anything

This is wrong. There are many studies that show that people who have a higher BMI are at risk for serious illnesses. For instance, the higher the BMI, the greater the risk of a heart attack. Most importantly, the reverse is true. If you decrease your BMI you decrease your risk of stroke and heart attack. Another study in women shows that women with a BMI over 29 have a 3.3 times greater chance of a fatal or non-fatal heart attack within the next eight years than women with a BMI less than 21. BMI values between 18.5 and 24.9 are considered normal. These results were adjusted for age and smoking status, meaning that comparisons were made between women of the same age and smoking status so any differences in heart attack risk could not be attributed to either of those factors.

Insights For Health Bottom Line: A high BMI increases your health risks for many serious medical conditions, but other factors can also affect those risks. BMI is a modifiable risk factor – something you can do something about to lower your risks.

Next time we’ll consider the myth that for some people a high BMI is normal.

For Your Health – Dr. Bob

BMI – Separating Facts From Fiction

From time to time I read comments or articles that are critical of judging a person’s weight by using the Body Mass Index (BMI). I have heard that there is a recent film that calls its usefulness into question. Being a physician, I thought I should clarify some of the more common misconceptions surrounding it. In my next few posts I’ll discuss some of the more common myths about the BMI and point out some facts to help you understand how it should be used and why it’s important:

Myth 1 – BMI Doesn’t Really Measure Obesity

Health care professionals will consider it and other measurements in assessing the proper weight range for an individual.

In my next post I’ll discuss another myth I’ve heard that the BMI really is not useful.

For Your Health – Dr. Bob

How Is Obesity Defined?

Body Mass Index (BMI) is a measure calculated from a person’s weight and height. It provides a reliable indicator of body fatness for most people and is used to screen for weight categories that may lead to health problems. BMI is calculated by dividing your weight in kilograms by your height in meters squared. That number should be between 18.5 and 24.9. The National Institutes of Health has defined certain classifications of weight based upon the BMI:

Classification	BMI Range
Underweight	Less than 18.5
Normal	18.5 – 24.9
Overweight	25.0 – 29.9
Obese	30.0 – 39.9
Extreme Obesity	Greater than 39.9

According to a report released on July 7, 2011 by the Trust for America’s Health and the Robert Wood Johnson Foundation, two-thirds of all adults and about a third of all children and teenagers in the United States are overweight or obese. In fact 16 states have obesity rates over 30%. Colorado has the lowest rate at 19.8%. Twenty years ago no state’s obesity rate exceeded 15%. Indeed we have an epidemic!

You should discuss with your physician whether your goal should be to attain a normal BMI. For people with a lot of muscle mass, such as trained athletes, a healthy BMI may actually be somewhat higher than what the table would indicate. For most people, however, these categories are a useful guide.

Another body measurement that is related to health risk is the waist circumference. It seems that the location of fat makes a difference as far as health risk. Fat in the waist carries a greater health risk than fat in hips or thighs. Scientific studies have shown that people whose waists exceed the targets in the table below have a higher risk of health problems.

Gender	Healthy Waist Circumference
Men	Less than or equal to 40
Women	Less than or equal to 35

In my next post I’ll talk about the health risks from being overweight.

For Your Health – Dr. Bob