The first lady, in an opinion piece published Thursday in The Wall Street Journal, wrote that the conventional wisdom that "healthy food simply didn't sell" has been proven wrong.
"Every day, great American companies are achieving greater and greater success by creating and selling healthy products," she said, citing the success of Walmart.
The company has reported in the past two years that it has cut consumers' costs for fruits and vegetables by $2.3 billion. It has also slashed by 10 percent the amount of sugar in its products, Obama said.
She noted a Hudson Institute report that healthier foods "have generated more than 70 percent of the growth in sales for consumer packaged-goods companies."
The increased consumption of healthier foods is beginning to show results, Obama said.
Obesity rates for Mississippi elementary school students have dropped 13 percent, while declines in childhood obesity have also been recorded in other states, she added.
"It's clear that we are moving in the right direction," Obama said, urging American businesses to "dig deeper, get more creative and find new ways to generate revenue by giving American families better information and healthier choices."