Another alternative is to buy organic products, which do not contain GM ingredients. Buy products that certify that all of the ingredients are organic. In spite of recent USDA proposals to soften organic regulations by alllowing GM crops, the idea was roundly rejected by the public. Express your concerns to food producers. Contact the makers of your favorite products and let them know you don't want GM foods.
Most product labels offer a toll-free number.
Inform government agencies that you expect labeling and testing of GM foods that are on the market. Include the docket number. You can read part two here. Due to space limitations, the references are not reproduced here. Readers who would like a copy can contact the author through Hampden Park Foods.