Five years after she launched Let’s Move, Michelle Obama’s willingness “to make a complete fool of myself” is the most visible part of her campaign to end childhood obesity. She’ll dance with a turnip, or Big Bird, or Jimmy Fallon.

Behind the scenes, however, she has cultivated partnerships with big business to cut salt, sugar and fat from food. This network of corporate relationships is unlike that of any previous first lady and has helped her sidestep a Republican Congress resistant to the administration’s public health policies.

The corporate allies she has sought may in some cases share her views, or, at least, see gains for themselves in their public association with her healthful-eating mission.

Her tactics are controversial – to what extent should a first lady lend her status and imprimatur to commercial enterprises? – but also strategic. She and her aides hope they will yield lasting results.

Congress has some sway over how Americans eat. But the nation’s food purveyors, including Wal-Mart, the biggest of them all with $206 billion last year in food sales – and one of Obama’s key partners – almost certainly have more influence and will respond more nimbly to consumer demand.

Like the president, Michelle Obama has less than two years to secure the gains she has made and her legacy as a first lady who accomplished work more substantive than driving fashion choices and YouTube traffic. Obesity rates for children between the ages of 2 and 5 decreased between 2003 and 2012, according to the Centers for Disease Control and Prevention, and some states recently have reported making progress against obesity in disadvantaged children.

What hasn’t budged in 20 years is this: 1 in 3 American children are overweight or obese, a public-health crisis projected to deprive a generation of potential and to generate trillions of dollars in health-care costs.

To combat that, Obama has championed sweeping changes, some encoded in law and some imposed through federal regulatory powers, with a focus on both personal responsibility and helping the poor. Chain restaurants, movie theaters and take-out pizzerias are required to list calories on menus by the end of the year. The Food and Drug Administration is finalizing the broadest update to grocery nutrition labeling in 20 years.

The change that has provoked the most backlash is also the one mandated by a 2010 federal law that passed with broad bipartisan support. The school lunch program, which provides free and reduced-price meals to more than 21 million low-income children, now requires districts to serve more fruit, vegetables, whole grains, lean protein and low-fat dairy products.