Message to Mrs. Obama: Exercise Only Won’t Do the Trick

In February 2010, when the first lady announced a cam­paign to “end child­hood obe­sity within a gen­er­a­tion,” I was imme­di­ately skep­ti­cal. I wor­ried that “Let’s Move” sig­naled an over-emphasis on phys­i­cal activ­ity, a much safer polit­i­cal issue than eat­ing habits, and one that Big Food gladly embraces.

But when I took a closer look, I was pleas­antly sur­prised to see that three of the four issues areas ini­tially iden­ti­fied by the cam­paign were food-related. (A fifth issue has since been added.) The goals or “pil­lars” of the cam­paign are: 1) improv­ing access to healthy, afford­able food; 2) pro­vid­ing healthy food in schools; 3) empow­er­ing par­ents and care­givers; 4) increas­ing phys­i­cal activ­ity; and 5) cre­at­ing a healthy start for children.

It’s hard to argue with any of those wor­thy causes, and it’s impor­tant to have the first lady bring atten­tion to issues such as food deserts, and to serve as a national spokesper­son in a way we’ve not seen before. I have also given praise where praise was due, such as when the first lady rec­om­mended — as part of a check­list for day­care cen­ters to fol­low — sig­nif­i­cant lim­its on screen time for children.

And while the White House insists that food is very much still on the agenda, it’s hard to ignore the poten­tial for pol­i­tics going into an elec­tion year. (When New York University pro­fes­sor Marion Nestle recently dared to ques­tion the first lady’s renewed empha­sis on exer­cise, she got set straight by White House chef and Let’s Move advi­sor Sam Kass; that’s how touchy this sub­ject is.)

Exercise is fun, but it doesn’t match the science

Putting pol­i­tics aside for a moment, let’s talk research, which can often get lost in the shuf­fle or, worse, dis­torted by cor­po­rate interests.

Obesity expert Dr. Yoni Freedhoff, assis­tant pro­fes­sor of fam­ily med­i­cine at the University of Ottawa, says the first lady’s focus on phys­i­cal activ­ity to help “end child­hood obe­sity in a gen­er­a­tion” is mis­guided. More impor­tantly, he says, it’s not evidence-based.

He pointed me to many sci­en­tific stud­ies show­ing that phys­i­cal activ­ity, while impor­tant for other rea­sons, has not been shown to be effec­tive in pre­vent­ing child­hood obe­sity. (See here, here, here, and here.) On the con­trary, data shows that an increase in food intake alone explains the rise in obe­sity in children. 

Children’s diets have changed so dras­ti­cally in the last few decades, with the increase in calo­ries, for exam­ple, due to soda and fast food so large, that mod­er­ate increases in exer­cise are not likely to make a difference.

As Freedhoff explains, it’s a “tes­ta­ment to the sim­ple fact that it’s far more dif­fi­cult to burn calo­ries than it is to con­sume them.” 

To be clear, exer­cise does have many health ben­e­fits; it just shouldn’t be used to dis­tract us from over­con­sump­tion and mar­ket­ing of junk food. Also, lots of skinny kids suf­fer from diet-related health prob­lems, includ­ing aller­gies.

So if sci­ence isn’t dri­ving the exer­cise band­wagon, what is?

Playing it safe

After nearly two years, it’s clear that Let’s Move is steer­ing away from any­thing that chal­lenges the food indus­try. In fact, the cam­paign orga­niz­ers appear eager to form cor­po­rate part­ner­ships. For exam­ple, the first lady hailed Walmart’s so-called “healthy food ini­tia­tive” as a new “nutri­tion char­ter.” Of course, Walmart hasn’t exactly kept its promises when it comes to the envi­ron­ment, so we have lit­tle rea­son to trust the com­pany when it comes to nutrition.

Click here to read the rest of this arti­cle at Grist.org.