The Grocery Manufacturers Association estimates that a whopping 75 percent to 80 percent of conventional processed foods now contain GMOs. Even foods that don’t list corn, soy, or canola as a main ingredient can still be GMO-laden because of sneaky additives like ascorbic acid, sugar from beets or corn, lactic acid, and more.

 “Products with seemingly low-risk ingredients often have ones that could contain GMOs,” says Courtney Pineau, assistant director for the Non-GMO Project, the leading non-GMO certification organization. “It’s surprising where GMOs can pop up, and it’s changing all the time.” Translation: If you’re not buying USDA Organic products—which, by definition, exclude GMO ingredients—you’re probably eating GMOs.

The jury’s still out on whether eating GMOs cause harm. Smatterings of animal studies suggest negative repercussions. For example, one study published in the Journal of Organic Systems found that pigs given GE feed had significantly more stomach inflammation than pigs eating non-GE feed. Another two-year study found that rats fed GMOs had a higher chance of developing mammary tumors.

Regardless of the GMO safety issue, non-GMO proponents insist that labeling foods containing GMOs is paramount. Nearly 60 countries, including Australia, Japan, and France, mandate GMO labeling. But the United States does not.

That lack of transparency doesn’t sit well with a lot of people. In 2012, products sporting the Non-GMO Project Verified seal fetched $2.4 billion in sales, and since Whole Foods announced its labeling initiative, the Non-GMO Project has fielded a surge of inquiries from natural manufacturers wishing to get their products certified GMO free.

The FDA maintains its position that GMOs are harmless, claiming there’s no evidence to substantiate adverse health effects. But the opposite is also true: There’s inconclusive evidence to show that they’re safe. According to a growing base of scientists, food experts, and citizens, you have the right to know what’s in your food and to choose or avoid products based on that knowledge.