UPDATE: August 9, 2013: It's not often -- heck, it's not even "rare" -- when The New Yorker talks about WIC (Women, Infants & Children, a nutrition/parental education program of the U.S Dept of Agriculture), but it is today, as Margaret Talbot writes in "Obesity Lessons for Liberals and Conservatives":
...We can’t say for certain what accounts for the [drop in preschool obesity, see history below]change, but one likely explanation is worth thinking about, not least because it challenges entrenched claims from both the left and right that have blocked innovations in public-health policy.
In 2009, the U.S.D.A. made a major revision in the list of foods that could be bought with coupons from the federal program known as W.I.C. (short for the Supplemental Nutritional Program for Women, Infants, and Children). The new package included more healthy items (fresh, frozen, and canned fruits and vegetables, whole-grain breads and cereals, and low-fat milk) and fewer dubious ones (sweetened juices, cereals and breads that are not whole-grain). This was significant not only because the changes were so purposefully aimed at improving nutrition for low-income Americans but because W.I.C. serves so many of them—fifty per cent of American infants, twenty-five per cent of children under five, and twenty-six per cent of postpartum women are enrolled in the program.
In many of the low-income neighborhoods where women and children rely heavily on W.I.C., supermarkets are few and far between. Residents with limited funds for transportation are often forced to shop at the kind of gas-station quick marts and dusty-shelved corner stores where they can find plenty of beef jerky, chips, and soda and, other than a bruised banana or two, not much in the way of produce. But when a team of researchers from Yale University’s Rudd Center for Food Policy and Obesity studied W.I.C.-authorized stores across Connecticut, they found that the stores had responded to the new rules by “improving the availability and variety of healthy foods.” The businesses “found a way,” as the researchers from Yale put it, to make room for low-fat milk on their shelves, and to stock fruits and vegetables and whole-grain breads and other products they had not sold before. In so doing, they revealed a previously unsatisfied consumer demand. The researchers found that nearby stores that did not accept W.I.C. also started offering healthier foods, either because they now had new supply chains to take advantage of, or because customers were now asking for them, or both.
Marlene Schwartz, the director of the Rudd Center, above, thinks the W.I.C. reforms surely played a role in the reduction of obesity reported this week. The sheer number of families affected is part of the reason. And for two- and three-year-olds, who don’t need as many calories, a relatively small change—a switch to low-fat milk, a dip in the amount of sweetened juice they’re chugging—“can be pretty significant.” ... In subsequent studies, says Schwartz, the Yale team has found that the W.I.C. reforms “really make a difference in what people purchase.” There were worries that families would drop out of the program or undermine the purpose of the changes by using their own money to buy lots of less healthy foods. But, by looking at scanner data from grocery stores, the Yale group has determined that this isn’t happening..[The above is an excerpt; we recommend the entire article.]
August 6, 2013: "Small but significant" decreases in obesity among low-income preschoolers in 19 of 43 surveyed states and territories between 2008-2011 have been noted in "Vital Signs," a report released today detailing data from the Pediatric Nutrition Surveillance System of the US Centers for Disease Control and Prevention. California was among the states with improved numbers. In reporting the data, Sabrina Tavernise wrote in the New York Times:
...“We’ve seen isolated reports in the past that have had encouraging trends, but this is the first report to show declining rates of obesity in our youngest children,” said Dr. Thomas R. Frieden, director of the Centers for Disease Control and Prevention, which prepared the report. “We are going in the right direction for the first time in a generation.”
The cause of the decline remains a mystery, but researchers offered theories, like an increase in breast-feeding, a drop in calories from sugary drinks, and changes in the food offered in federal nutrition programs for women and children [WIC]. In interviews, parents suggested that they have become more educated in recent years, and so are more aware of their families’ eating habits and of the health problems that can come with being overweight...