As many companies that produce GMOs are suing any state that attempts to label products that contain GMOs, it is difficult to know where the products are hiding.
The easiest way is to look for the USDA Organic label which in its guidelines prohibits genetically modified food from using the label. Read More
You can also purchase food from countries like Spain, Germany, and Italy that require labeling of GMOs in their products.
Several sites offer nonGMO product lists:
And I think there might even be an app for it. Check here
Lastly, you might consider your local farmers’ markets and talk to the people who grow the food. Googling ‘Farmers markets’ is the easiest way to find one near you, but there are eat local movements, Community Supported Agriculture (CSA), and Buying clubs.
Will it be more expensive? Yes, but since most grocery stores now carry Organic products (our Fry’s and Safeway do), these items also go one sale and you can stock up. The app will let you know which conventional products are nonGMO, saving you even more.