Beware of so-called "natural" foods that claim to be vegetarian or "all natural." If they're made with corn, soy or canola and they're not ORGANIC, then they are almost certainly made with GMOs.
Many of these "natural" foods are sold at apparently healthy stores like Whole Foods or Trader Joe's. But that doesn't mean they don't contain GMOs! The shelves at Whole Foods contain a plethora of products with genetically engineered food ingredients, so read the labels and buy USDA organic, which is reliably non-GMO.