(Bloomberg News) Wal-Mart Stores Inc., SuperValu Inc., Walgreen Co. and regional retailers are making fresh commitments to expand the selection of more healthful foods in underserved areas, first lady Michelle Obama said in a statement.

Wal-Mart, the world's biggest retailer, is pledging to open or expand as many as 300 stores by 2016 under Obama's campaign to provide more nutritious food in poor rural and urban areas.

In an announcement planned for later today, Obama said the commitments "will provide access to healthy, affordable food to millions of people in underserved communities," a statement from her office said.

Walgreen, the largest U.S. drugstore chain, plans to convert "at least 1,000" of its 7,733 stores in the U.S. and Puerto Rico to include selections of whole fruit and vegetables at so-called "oasis stores," the statement said.

SuperValu, the Eden Prairie, Minnesota-based owner of Save- A-Lot and Albertsons grocery stores, is pledging to open 250 Save-A-Lot stores in the next five years in areas "with limited or no access to healthy foods," Obama said.

"These stores estimate that they will create tens of thousands of jobs and serve approximately 9.5 million people in these communities throughout the country," the first lady said in the statement. About 23.5 million Americans, including 6.5 million children, now live in low-income areas that lack stores likely to sell affordable healthful foods.

Studies show that limited access to healthful food choices can lead to poor diets, higher levels of obesity and other diet- related diseases, Obama said.