Wednesday, June 18, 2008

Nothing Changed But Her Age

In my earlier post, about the little girl, absolutely nothing changed in two months, other than she was now 3-years 10-months old and before was 3-years 8-months old.

I charted the hypothetical little girl at 3-years 8-months as standing 38" tall and weighing 34.5-pounds - placing her in the 84th percentile for BMI for age, the top of the "normal healthy weight" classification. With no upward growth and no weight gain in two months, this same child would now be in the 85th percentile for BMI for age, making her "at risk for overweight" in some circles, or simply "overweight" in others.

Interestingly, if we calculate her traditional fall on the height and weight charts, her weight at 3-years 8-months places her in the 59th percentile for weight for age; at 3-years 10-months it's dropped to the 52nd percentile for weight for age. Yet this child is now labeled as being among the statistics of overweight and/or obese children.

The dirty little secret about children's BMI charts is they slope downward starting at age 2 until about age 6! Take a look:

How often do we read or hear how parents are totally blind to their child's weight problems?

How many out there realize the difference between "normal healthy weight" of a three year old girl and 'at risk for overweight" (or overweight) is just 0.5-pounds, to be classified "overweight" (or obese) it's just one more pound if you use the BMI for age chart?

How many realize that within as short a period of time as a month, with no gain or loss and no upward growth a child can move from one category, normal healthy weight, up to overweight?

Yet this is the "gold standard" we parents are told is best to determine if our child is overweight or obese, in need of intervetion to prevent them from becoming an obese adult!

What do you think?

You can go play with the calculators available online:

Children's BMI Calculator

Children, Age 2 to 20, Growth Chart Percentiles Calculator


  1. Anonymous6:00 PM

    so the weight between normal and obese for kids is only 1 1/2 pounds? Holy shit!

  2. Ridiculous. How could any doctor not see that this is ridiculous?? How???

  3. Anonymous11:23 AM

    This is truly ridiculous but the practice of medicine has been reduced to 2 things: following guidelines and avoiding malpractice. No common sense is allowed!

  4. Not to mention that any individual's weight can fluctuate that much from one week/day to the next depending on the amount of carbohydrate consumed (i.e. water retained), regularity, and so forth.

    But I do think the message is getting out there. I here good observations from many parents. More need to know though.

  5. Anonymous10:07 PM

    "Anonymous said...
    This is truly ridiculous but the practice of medicine has been reduced to 2 things: following guidelines and avoiding malpractice. No common sense is allowed!"

    nor obviously is the practice of medicine - when did doctors become nothing but drug pushers for the pharmaceutical companies?

  6. i have to agree talk about i fine line between healthy & obese..

  7. Anonymous5:08 PM

    I think that all children grow differently and that if you worry about these charts you just may go crazy. But I do disagree with you on one thing. The part of the chart you have a problem with clearly implies that the child's height should be increasing at a faster rate than the weight increase of the child. That's why you get a u-shaped curve.

  8. Great suggestions and some interesting comments to boot.Thanks for the insights on children's BMI. BMI calculator throws some light on unhealthy body weight.