July 8, 2014 at 1:00 am

To Your Health

BMI is not a total picture of one's health

Dear Dr. Roach: About seven years ago, my blood pressure was high, and I was overweight and in a stressful job.

I quit the job, my blood pressure went down, and I lost over 40 pounds. I have kept the weight off all these years. I work part time, standing on my feet about 25 hours a week. My doctor has been happy with me. At my last appointment, I was told my BMI is too high and that I am obese.

Where did this “BMI” come from? I am 5 feet, 6 inches tall and weigh 194 pounds. I am a large-framed woman (I delivered 12-pound babies through NATURAL childbirth!). Now I feel like I should forget it and go back to eating what I want, when I want!

P.S.

Dear P.S.: BMI, the body mass index, is a way of determining obesity by standardizing weight for people of different heights. It is equal to weight (in kilograms) divided by height (in meters) squared. BMI predicts the development of Type 2 diabetes, heart disease and even overall mortality rates moderately well. It is certainly not a perfect measurement. Someone whose BMI is obese (over 30) might have very little body fat; he or she might be very muscular or have larger bones than another person of the same height.

Some physicians measure waist circumference, since that looks at abdominal fat, and research shows that using both measurements gives a more complete picture of health.

Personally, I congratulate you for getting and keeping off 40 pounds, and think you made a wise investment in your health by finding a less-stressful job. Your BMI is 31, just in the “obese” range. However, women of your BMI but whose waist circumference is less than 31.5 inches (80cm) have a much lower risk of medical complications later than those with a waist circumference above 31.5 inches.

Just by the way, having babies that large does indicate an increased risk for Type 2 diabetes later in life. Your doctor hopefully is checking you periodically. Getting regular exercise and eating a good diet reduces your risk for Type 2 diabetes and heart disease, so please don’t get frustrated by this single, incomplete measure of your health.

Dear Dr. Roach: I suffered from a very painful case of plantar fasciitis for longer than a year when my husband and I (both in our 40s) discovered that we were exp­ecting a baby. I was terrified over the prospect for several reasons, including the already painful state of my feet. It turned out that my plantar fasciitis was completely cured by the end of my pregnancy.

Now, at 47, with a darling 3-year-old, I’m wondering if there is any way of preventing the condition from returning. My OB/GYN guessed that perhaps the hormones that make a pregnant woman more “stretchy” is behind my cure. Do you have any ideas about this?

B.R.

Dear B.R.: Plantar fasciitis is an inflammation in the strong band of connective tissue that runs from the heel to the toes and supports the foot. The major symptom is pain with walking, especially with the first step of the day.

Pregnant women are indeed more likely to suffer from plantar fasciitis. Most authorities feel it is the relatively fast weight gain of a normal pregnancy, but some blame the hormone relaxin, which loosens the pelvic and other ligaments. This can change your gait and cause abnormal stresses on the feet, causing plantar fasciitis. Your obstetrician is suggesting that relaxin is acting on your already-existing plantar fasciitis, which I haven’t heard of, but it is an interesting thought.

For prevention, regular stretching of the calf muscles, wearing shoes with good support and maintaining a healthy weight can help prevent recurrence.

Email questions to ToYourGoodHealth@med.cornell.edu.