What We Don’t Know About Obesity

Published on: 13:04PM Dec 15, 2010

President Obama signed the Child Nutrition Act earlier this week, the culmination of a year-long effort by a lot of people – including his wife – to improve the nation’s collective health and weight in general, and the quality of school kids’ lunches in particular.

The “Healthy, Hunger-Free Kids” bill authorizes an additional expenditure of six cents per typical school lunch, with the goal of making “better” foods more common in public schools.  It also places restrictions on when and where foods of dubious nutritional quality – for all intents and purposes, what we usually refer to as junk food – can be sold or offered in schools.

This is all well and good, as the nation fights a critical battle against obesity, which has gotten particularly scary in young people because it’s become so much more common.  And yet I have to wonder how much this top-down effort at regulating the types of foods served to kids will really help.

The reason I say this is that we still don’t really have a clear sense about whether the obesity crisis is due to what we’re eating, or what we’re not doing to work it off.  It’s a chicken and egg argument that has gone round and round, and the usual response is that, well, it’s both that we’re eating too much – especially too much of the wrong stuff – and we’re doing too little to exercise and get outside and burn off those calories.  But it seems like knowing a precise answer to this conundrum is the necessary first step in helping address it.  Otherwise, scarce public policy resources may be directed towards things that aren’t really all that valuable.

Clearly, soda consumption among young people has increased in the past generation.  It probably plays a part in adding to the total caloric load, particularly in our juvenile population.  But soda’s been around for a century.  And now there’s this new report from the Archives of Internal Medicine which shows that taxing sugar-sweetened sodas would only have a marginal impact on people’s weight – just one pound less. This report is a blow to the bandwagon notion that if we just restrict or tax the heck out of soda, we’ve vanquished the main villain in the fat fight. 

Then you have people who go after the effect that farm programs supposedly have on public health.  Back in the summer, there was this stunningly misinformed quote in a story the New York Times ran on this topic.  Barry Popkin, a professor at the University of North Carolina, said that:

“If we cut the subsidy on whole milk and made it cheaper only to drink low-fat milk,” he says, “people would switch to it and it would save a lot of calories.”

But there is no subsidy for different types of milks, either their production, or their consumption.   In most supermarkets, a gallon of whole milk typically costs the same, or in some cases, MORE than skim milk.  In fact, in the new school lunch bill basically says schools can only serve nonfat or low-fat milk.  And if you look at the longer term trends, whole milk consumption has plummeted, from 14 gallons per capita in 1985, to six last year, while low- and non-fat varieties have risen in popularity during the past 25 years, from 12 gallons then, to 15 gallons per person today.

That statement, by a nutrition expert no less, reminds me of what Mark Twain said more than 100 years ago:   "It ain't what you don't know that gets you into trouble.  It's what you know for sure that just ain't so."  How can we have clear understandings about the policy environment when assertions of fact just ain’t so?

NPR commentator John McWhorter also weighed in this week on the obesity topic, and makes an interesting point that access to healthy foods, even in the poorest parts of the inner city, are not necessarily the be-all and end-all of this process.  He states that a cultural shift in what foods we prefer is what it will take to change the overeating, underexercising vicious circle.  And that change will entail far more than more servings of carrots and less of Coke.

This obesity policy issue reminds me a great deal of the recent debate over the budget deficit, and how much of shrinking that fat monster is due to a need for more taxes, versus less spending:  it’s much less about the specific numbers involved, and much more about societal values and priorities.  And there are no clear answer in that, just firmly-held opinions that make finding clear answers all the more difficult.