An FDA ruling approving the sale of genetically modified salmon has recharged the debate over the future of our food. But GMOs, or genetically modified organisms, have been part of our diet for years.

The Grocery Manufacturers Association says up to 80 percent of processed food sold in the U.S. is genetically modified, and most of it is not labeled.

The CEO of Monsanto, one of the world’s largest producers of genetically modified seeds, says the company is committed to innovation in agriculture, but critics say it should be more transparent.

“I think part of the challenge is there’s such misinformation of where food comes from… between what arrives on a plate and farmers do,” said Monsato’s CEO Hugh Grant. “So I think for companies like mine, we’ve got to work out in explaining what agriculture is and where food comes from.”

According to an Associated Press-GfK poll, 66 percent of Americans support requiring food manufacturers to put labels on products containing GMOs. But Monsanto spent millions of dollars, lobbying against a GMO labeling ballot initiative in Colorado and Oregon.

Grant says states’ adoption of mandatory GMO labels results in “confusion” and “more expenses,” rather than transparency.

“A deep concern is that we’ll end up with a patchwork quilt of state-by-state regulations where you’ll end up in a place where you can’t move a can of soup from one state to the other,” Grant said. “The consumer is going to end up paying four or five hundred dollars more a year on their grocery bills.”