The sharp decrease sounds encouraging, remarkable even until you consider a few more facts and figures. Changes or improvements run the risk of sounding more impressive untethered from the raw data especially when headlines scream the obesity rate "plummets" as did the New York Times so let's look at some of the numbers.
In 2004, 13.9% were obese.
In 2012, 8.4% were obese.
These details didn't prevent WebMD from announcing U.S. Obesity Rate Shows Signs of Leveling Off suggesting an improvement across the board.
USA Today, written at the level for school children*, actually made the effort to make this important point about the results:
Thomas Robinson, a professor of pediatrics at Stanford University, notes that obesity rates among kids ages 2 to 5 have gone up and down significantly over the past decade. Although the survey included 9,120 people, only 871 were ages 2 to 5 years old. And of those children, only about 70 were obese. So in any given year, a relatively small number of children can have a big impact on obesity rates.
If children have improved their waistlines (I know, how awkward is that phrase?) then don't get too optimistic because no one can fully explain how or why this happened if it is in fact a true drop (as opposed to a small, unreliable sample).
Here's how the New York Times explained the lower childhood obesity:
There was little consensus on why the decline might be happening, but many theories.
Children now consume fewer calories from sugary beverages than they did in 1999. More women are breast-feeding, which can lead to a healthier range of weight gain for young children. Federal researchers have also chronicled a drop in overall calories for children in the past decade, down by 7 percent for boys and 4 percent for girls, but health experts said those declines were too small to make much difference.
Yet the New York Times couldn't resist mentioning them.
But the news organization did have the good sense to find and cite at least one expert, one that put his money (and research funding) on Americans buying lower-calorie food (but apparently not serving it to older kids or eating it themselves?). The same expert also credits changes in the Special Supplemental Nutrition Program for Women, Infants and Children. The program cut funding for fruit juices, cheese and eggs while increased funding for whole fruits and vegetables.
The Washington Post noted a lot of these same reasons and it appears the lead researcher might have mentioned them first.
Perhaps similarly unconvinced of the above explanations, the NY Times defaulted to the all-purpose public health disclaimer:
Another possible explanation is that some combination of state, local and federal policies aimed at reducing obesity is starting to make a difference.
Who needs the Oscar's celebrity tweet photo bomb, the baby that hates Brian Williams or the random musings about Forty Somethings from that bestselling author/mom in France/parenting expert now mid-life expert, when child health news presents so much entertainment?
Did I mention that the NY Times worked in cancer, heart disease and stroke in the first sentence.The first sentence.
Obviously you and I have wasted time thinking about shrinking waists because no one knows why or even if they really are shrinking.
*I couldn't find much evidence behind this claim. I do remember when the paper debuted and all the fuss that it wasn't too demanding and that a 3rd grader, or was it 5th-grader, could read it. Check out this article on reading levels in various news outlets. Surprised?