Obama, who is spearheading an administration initiative on child obesity, praised members of the Grocery Manufacturers Association for reducing calories and salt in food.
"But I'm here today to urge all of you to move faster and to go farther because the truth is we don't have a moment to waste -- because a baby born today could be less than a decade away from showing the first signs of high cholesterol, high blood pressure, Type II diabetes, if he or she is obese as a child," she told the meeting of the trade association.
"So we need you all to step it up," said Obama, who sponsors local school children to help her maintain and harvest a garden on the White House grounds.
Grocery Manufacturers Association Chairman Richard Wolford, who is also chairman, president and chief executive officer of Del Monte Foods Company, said the group supported the initiative and had already done a lot.
"In recent years, our companies have reduced calories, sugar, fat and sodium in more than 10,000 products," he said in a statement. "They have also enhanced the nutritional profile of many products with the addition of whole grains, fiber or other nutrients and created the informative and convenient 100-calorie pack.
"Food and beverage companies have changed the way they advertise and market their products -- children under 12 now see significantly fewer food, beverage and restaurant ads on television. And at the same time, they are seeing more ads for soup, juice, fruit and vegetables."
Obama said companies need to do more.
"And we need you not just to tweak around the edges but to entirely rethink the products that you're offering, the information that you provide about these products and how you market those products to our children," she said.
President Barack Obama last month assigned Cabinet officers to come up with "a comprehensive interagency plan" and asked his wife to head a national public awareness effort.
Two industry groups, the American Beverage Association and the GMA, have pledged their help and earlier this month the beverage makers announced progress on getting sugary soft drinks out of schools.
The administration said last month it would provide $400 million for its Healthy Food Financing Initiative to eliminate "food deserts" where the only food sources are typically convenience stores or gas stations.
The US Centers for Disease Control and Prevention has found that 68 percent of U.S. adults are overweight and half of these are obese, with a body mass index of 30 or higher. A third of US children are obese.