"It's a very simple calculation that most of us can do in our heads," he said. For men and women, there is a baseline height and weight. For men, it is 5-foot-9 with a maximum weight limit of 175 pounds, meaning someone that height shouldn't go over 175 pounds. For women, it is 5-feet tall, with a maxium weight limit of 125 pounds.

Then you just figure out how much taller or shorter you are than the baseline. If you are a man, just add or subtract 5 pounds for every inch taller or shorter than 5-foot-9 you are. A 6-foot-tall man's maximum weight limit would then be 190 pounds (175 plus 15 pounds). Women should add or subtract 4.5 pounds for each inch they differ from 5-feet.

This is something people can remember, Fernandez said.

Meanwhile, researchers at the University of North Carolina at Chapel Hill's medical school have also been thinking about BMI. In a small study published in the September/October issue of the journal American Pediatrics, researchers found that parents are more likely to understand a BMI chart if it is color-coded like a traffic light.

Parents don't always know when their children are overweight or are gaining weight too fast. And when study participants were given a standard BMI chart, with percentiles and ranges, they had a much more difficult time figuring that out than a color-coded chart, the researchers said. The color-coded charts made more sense -- with green indicating healthy BMI, yellow showing more risk wand red putting the child is in an unhealthy zone.

Is simplifying BMI going to aid us in the war on obesity?

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