First Lady Michelle Obama is expected to make a major announcement regarding her campaign to combat childhood obesity on Tuesday.  Mrs. Obama will be joined by business leaders to make the announcement, which will impact “food formulation, availability and affordability,” White House food policy blog Obama Foodorama reported.

UPDATE: The White House announced Monday the First Lady’s event has been postponed and will be rescheduled.

Along with the recently enacted child nutrition reauthorization bill, which for the first time in three decades increased the reimbursement rate for school food above inflation, and allows for the U.S. Department of Agriculture to set nutritional requirements for all food sold in schools, improving the accessibility and affordability of healthy foods is one of the pillars of the Let’s Move! campaign.

“Here’s the thing–we can build shiny new supermarkets on every block, but we need those supermarkets to actually provide healthy options at prices people can afford,” Mrs. Obama told the members of the Grocery Manufacturers Association in 2010.

Responding to the First Lady’s call to action, 16 of the top U.S. food and beverage manufacturers announced last May they would work toward removing 1.5 trillion calories from the American diet annually by 2015, with a total of 1 trillion to be cut by 2012.

According to Obama Foodorama, Mrs. Obama’s announcement in the morning on Tuesday, Jan. 11 is both her first Let’s Move! event and first public event for 2011.

Mrs. Obama’s final public Let’s Move! event in 2010 was the special bill signing ceremony on Dec. 13 for the historic Healthy, Hunger-Free Kids Act, which passed during the lame duck session of Congress. Before that, on Nov. 29, Mrs. Obama launched Let’s Move Faith and Communities, a grassroots sub-initiative to encourage the vast memberships of congregations and community groups to join Let’s Move!”