If you only eat whole foods- meaning only one ingredient like an apple, potato, or broccoli, and you know that the seed source is non-GMO, you can rest assured you are not eating GMO's. However, many of us eat some processed foods, whether out of a package from the grocery store, or when we eat out. Without GMO labeling, unless you’re buying 100% organic, non-GMO verified foods, or whole foods without any processing which are not GMO there’s really no way to tell.
The Non GMO project website estimates that 80% of the food in America has GMO ingredients. Why is this number so high? Because #1 there are a HUGE number of processed foods in our food supply, and #2 processed foods are likely to contain ingredients like corn syrup and soy lecithin, which are most likely to be from GMO crops. The current American crops with Genetic Engineering include; sugar beets, soy, corn, canola, cotton seed, Hawaiian papaya, zucchini, yellow crock neck squash, and alfalfa.
For more information on which foods contain GMO ingredients click here to get the Non-GMO shopping List.