Wow. Just wow.

Researchers from the National Cancer Institute in Bethesda, Md. analyzed data from the National Health and Nutrition Examination Survey and found that nearly 40 percent of calories consumed by children ages 2 to 18 were empty calories… Half of these calories came from just six foods:
   *    Soda
   *    Sugary fruit drinks
   *    Grain desserts, such as cake, cookies and donuts
   *    Dairy desserts such as ice cream
   *    Pizza
   *    Whole milk, which is far fattier than skim.

Candy - flickr user TheFoodJunkGood for ABC News for spotlighting this.  But despite my initial surprise at the statistic, I suppose it’s nothing unexpected.  Researchers have been tracking the rising tide of obesity, both among kids and adults, for almost two decades.  And we’ve known for a long time that kids, like the rest of us, are eating an awful lot of junk food.

Yet in all the reporting I’ve seen on the topic, it’s rare to come across a compelling explanation of why we’re eating so many more empty calories than we used to. This latest article, for example, attributes unhealthy eating habits to:  “a lack of physical activity, parental and peer influences, and marketing by the food industry.”

Hmmm.  Speaking both as a data geek and as the parent of a 6 and 9 year old, those explanations simply don’t ring true.

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  • I almost feel as if the reporter is clutching at straws.  Sure, physical inactivity contributes to obesity; but unless I’ve missed something, there’s not much evidence that sloth itself makes kids drink more soda.  And while I don’t doubt for a second that marketing affects kids (see this NY Times article for proof), the food industry could market kale all day long and my kids will still prefer Kit Kats (though I did get a chuckle out of this baby carrot ad campaign). As for peer or parental influences—that just begs the question, since it doesn’t explain why parents and peers are buying and eating all those empty calories in the first place.

    food price inflation chartBut more importantly is what’s not on the list.  First and foremost are prices.  JUNK FOOD IS CHEAP.  In fact, it’s a heck of a lot cheaper than it used to be.  As the chart to the right shows, the inflation-adjusted price of oils and sweeteners has declined dramatically since the obesity epidemic began in earnest in the mid-1980s. 

    Here’s another way of looking at how incredibly cheap empty calories have become.  A bushel of field corn currently sells for a little less than $5 on the commodities markets.  That bushel contains 56 pounds of corn—enough calories to feed an adult human for about 50 days.  Yeah, yeah, people don’t actually eat field corn; it goes to animals, or gets processed into other products like high fructose corn syrup.  Still, the point remains:  the raw ingredients of junk food are so cheap that a person earning the US minimum wage can earn enough to buy a year’s worth of corn calories in a single day of work.

    One big reason why empty calories are cheap is that we produce a lot more of them than we used to.  Corn harvests have been trending upwards for a long time.  And looking at trends in “available” food calories per person since 1970, grains, oils, and sugars have skyrocketed.  (As far as I can tell, the “availability” of fruits and vegetables has also gone up over the last 40 years—yet even though we’re buying a few more veggies, we’re buying lots, lots more oils, sweets, and refined grains.)

    Second—and yes, I’ll go here—JUNK FOOD IS ADDICTIVE.  If my experience is any guide, kids crave sweets, refined flour, and fatty foods.  Not all of them, perhaps; but most of the kids I know love the stuff.  And I just don’t think it’s marketing or peer pressure that makes kids like ice cream (though I’m sure that effective marketing helps remind kids about the existence of ice cream—which is certainly a problem for parents trying to clamp down on the sweets).

    I blame evolution here.  Proto-humans didn’t evolve in an environment of agricultural abundance, so we’re programmed to consume easily digestible calories whenever they’re available.  Building up a store of fat was a hedge against starvation—a boon to kids’ health, not a bane.  But now that we’ve radically altered our food environment, an abundance of empty calories is creating all sorts of health problems.  (That said, the connection between weight and health is somewhat more complicated than is commonly believed.)

    So what’s a parent to do?  Junk food is cheap, abundant, easy to prepare, and to most kids, tasty—which creates a set of incentives that powerfully influence our choices about what we feed our kids, and what they’ll want to eat.  Yet most “solutions” to childhood obesity center around encouraging individual acts of willpower—with exhortations to eat better, exercise more, and generally swim against the genetic and economic tides. 

    I’m skeptical that that will do much. Far more powerful would be a different set of incentives—say, a pricing system that makes empty calories more expensive (as Eric Hess mentions here) but that does so in a way that didn’t undercut the ability of lower-income folks to feed their families.   As to the charge that this would be too much government meddling—well, the government has meddled for generations in agriculture, mostly in order to boost the production of empty calories.  Maybe, given the abysmal state of the US diet, some counter-meddling is finally in order.


    Candy image courtesy of flickr user TheFoodJunk, distributed under a Creative Commons license.