Re: “Low child obesity rate in Oregon a mystery” (TNT, 5-4).
The article contains a contradiction that demands an explanation. It states that a child is defined to be obese if he or she is in the 95th percentile (for body mass index). This means that the top 5 percent of the indicated population would be classified as obese.
The article goes on to state that 16 percent of the children in the U.S. are obese. It is mathematically impossible to have 16 percent of a population in the top 5 percent on any criterion. It would be like Lake Woebegone, where all the children are above average.
By looking at the actual survey being reported on, one can see that obesity was determined by the BMI for the 95th percentile in the year 2000. This says that the same BMI that would rank in the top 5 percent in 2000 puts a child only in the top 16 percent in 2007. This fact is crucial for understanding the report and should have been in the article in order for it to make sense.
One hopes that in the future news reports will include all the information needed to understand the issues. One expects better in a nation where making sense of data is becoming increasingly important.