U.S. shoppers are increasingly looking for "natural," "organic" and "grown in the USA" claims on food labels, according to the annual Eco Pulse survey conducted by the Shelton Group, an advertising and research firm that focuses on marketing green products to American consumers.

Among the 1,013 consumers who were asked what the best description to read on a food label is, 25 percent said they preferred to see "100 percent natural" or "all natural," 24 percent said they preferred "USDA certified organic" or "100 percent organic," and 17 percent preferred "Grown in the USA."

Although most consumers desire greener products, 71 percent of those surveyed said they almost always cost more, citing frustration with manufacturers for charging more.

"Most Americans will try a greener product if it is comparably priced and offered by a known brand," Shelton Group president Suzanne Shelton said in a press release. "But if helping the planet is the only benefit, most consumers aren't willing to pay the extra cost. In this economy, consumers prefer a greener wallet over a greener planet.”