In her pre-White House days, first lady Michelle Obama was not so different from the typical working mom at the end of a busy day: Why cook up a meal when a run through the drive-thru will do?

But as she confessed in an op-ed she wrote this week about health care reform on the website Shine, she was surprised when her daughters’ pediatrician advised her to pay better attention to their diet because their BMI numbers were going up.

“I didn’t really know what BMI was,” Obama wrote. “And I certainly didn’t know that even a small increase in BMI can have serious consequences for a child’s health.”

BMI or Body Mass Index is a standardized estimate of an individual’s relative body fat that is calculated from his or her height and weight and also can be used to determine how at-risk a child may be of becoming obese.

“A percentage too low may indicate hunger and poor nutrition, and a percentage too high can lead to diabetes, heart disease and other health issues,” wrote Obama.  “I was fortunate that our pediatrician was paying attention to the trends of childhood obesity, because I never would have known to ask for a screening on my own.”

According to the Campaign for Healthy Kids, 35.9 percent of African-American children age 2 to 19 are overweight or obese and 11.4 percent age 2 to 5 are obese. This makes them more likely to develop such conditions as diabetes and other chronic diseases. The Affordability Care Act requires new insurance plans to cover preventive services like BMI screenings without any kind of deductible, co-pay or co-insurance.

“Ask for a BMI screening so that you can catch any problems early on. Make sure you’re getting the care you need to stay healthy yourself and stop health problems before they become emergencies,” Obama urged. “Together we’ll all stay healthier and raise a generation of happy, healthy kids.”

(Photo:  Mark Wilson/Getty Images)