Ideal Body Weight & BMI

The body mass index (BMI) has changed how ideal body weight is assessed. Before a 1972 study by University of Minnesota professor Ancel Keys showed there was a connection between the BMI equation and obesity-related diseases, the weight-for-height tables were the most common measure of determining ideal body weight, as reported in "Beyond BMI," a Slate magazine investigative article. The BMI has many flaws, according to "Beyond BMI" and the Centers for Disease Control and Prevention (CDC).

Theory

The BMI is based on a theory that the correlation between weight and height squared is an accurate way of measuring body fat. When your BMI, which is your weight in pounds divided by your height in inches squared and then multiplied by 703, is between 18.5 and 24.9, you are considered to be at your ideal weight. You are considered to be below your ideal weight or underweight when your BMI is below 18.5, above your ideal weight or overweight when your BMI is 25 to 29.9 and obese if your BMI is at least 30.

History

The weight-for-height tables had different ideal weights for men and women who were the same height and different ideal weights for people with small, medium and large body frames. The BMI never distinguished between body frames, but the National Institutes of Health's (NIH) recommendations that men and women were at high risk when their BMI was at least 27.8 and at least 27.3 respectively were accepted by the medical community, according to "Beyond BMI." In 1998, the NIH decided that the at-risk thresholds for men and women should be identical.

Ideal Weights

A chart that translates the BMI's figures into ideal weights for people who are 4 feet 10 inches to 6 feet 4 inches tall is available at the NIH's website. Your ideal weight when your BMI is 18.5 to 24.9 is 97 to 127 pounds if you're 5 feet tall and 148 to 193 pounds if you're 6 feet 2 inches.

Warning

You should not relax if your BMI shows you are at an ideal weight and should not panic if your BMI shows you are overweight, according to the CDC, "Beyond BMI" and the "Essentials for Health and Wellness" book. The CDC reports that you can have a high BMI if you have a lot of muscle because the BMI doesn't distinguish between muscle and fat. "Beyond BMI" reports that waist circumference is a better measurement of fat than BMI. "Essentials" reports that women have more fat than is physiologically essential.

Expert Advice

You can reduce your BMI until you achieve a more ideal body weight by eating slowly, controlling your snacking, managing your daily food sources and controlling your home environment, according to "Essentials." The book's recommendations include putting down your eating utensils between bites, drinking a large glass of water before snacking, buying only groceries that are on a list and going into the kitchen only for "food-related activities."