Tough Bunnies

For the study, Lewis used data on prices charged at about 420 service stations in the San Diego area from January 2000 to December 2001. The data were collected by the San Diego-based Utility Consumers' Action Network, which describes itself as a consumer watchdog group. Data on wholesale gas prices paid by the stations were obtained from the Energy Department, he writes in a working paper available on his Web site.

Ironically, consumer buying patterns put more money in the pockets of gas station owners when prices are falling than when they are rising. Lewis found that profit margins were highest when the wholesale price of gas was dropping and consumers stopped bargain-hunting. That eases the pressure on station owners, which in turn allows them to keep prices high, thereby increasing their profit margins.

Never mind about gas selling for $3 a gallon. It's when tomatoes top $2 a pound that we should really worry -- at least those of us who are concerned about the rate of obesity in children.

A new study by two Rand Corp. researchers found that young children who live in communities where fruits and vegetables are expensive are more likely to gain excessive weight than children who live in areas with less costly produce. That finding helps explain the growing incidence of obesity in children over the past 20 years, a time when the cost of fruits and vegetables has increased faster than other food prices as well as the cost of living, asserts Roland Sturm, a senior Rand economist and lead author of the study published in the journal Public Health.

The study by Sturm and economist Ashlesha Datar also was remarkable for what it didn't find. The researchers couldn't make any link between obese kids and the presence of many convenience stores, full-service restaurants, fast-food restaurants or grocery stores near their homes. Advocacy groups have suggested that such a link exists, they reported.

The research team examined excessive weight changes in 6,918 children in kindergarten to third grade from 59 metropolitan areas around the United States. The researchers then compared the weight gain figures with the relative price of fruits and vegetables in each of the areas studied. The data was collected by the federal government as part of its Early Childhood Longitudinal Study.

Where do fruits and vegetables cost the most, relative to the price of other food and necessities? The winner: Mobile, Ala., where children gained about 50 percent more excess weight as measured by body mass index (a ratio of weight to height) than children nationally, Sturm reported.

Fruits and vegetables were relative bargains in Visalia, Calif., where children's excess BMI gain was about half the national average.

morinr@washpost.com