GM foods, or genetically modified foods, contain genetic material has been altered for a specific purpose. The World Health Organization notes that those purposes include resistance to viruses, herbicides and insects. A number of major U.S. crops are composed largely of genetically engineered plants, the most prolific being corn, soy, sugar beets and canola.
Major GM Crops
The Non-GMO Project lists corn, soy, sugar beets, canola, papaya, zucchini and yellow summer squash as having a high risk of being genetically modified. About 90 percent or more of corn, soy, canola and sugar beets are genetically modified, in terms of total production. Each of these crops is highly versatile and nearly ubiquitous throughout the food system.
Corn can be found in thousands of consumer foods in its most prevalent form -- high-fructose corn syrup. A 2004 study published in the "American Journal of Clinical Nutrition" notes that high-fructose corn syrup accounts for 40 percent of total sweeteners added to foods and beverages. Examples of foods that are likely to contain high-fructose corn syrup include soft drinks, fruit juice drinks, cereals, breads, candies, flavored yogurts, ice cream, crackers, pastries, cough syrups, jellies, jams and granola bars.
The GMO Compass website notes that soy is used as the basis for a large number of ingredients and additives. Soy is commonly used as an emulsifier -- an additive that better allows ingredients to be combined together. Soy can be used for its vitamin E content, and it's sometimes used as a protein source in foods. Examples of foods that are likely to contain soy include margarines, chocolate, baked goods, vitamins, bread, pasta and other processed foods.
According to the U.S. Department of Agriculture, sugar beets are a leading raw material for the production of sugar in the United States. In 2010, genetically modified varieties of sugar beets represented around 95 percent of the total planted area for the crop. Any food that lists sugar as an ingredient has a high probability of containing sugar derived from genetically modified beets.
After soybean oil and palm oil, canola oil represents the third-largest source of vegetable oil in the world, the USDA reports. With approximately 90 percent of all U.S. canola oil produced from genetically modified canola seed, consumers are at a high risk of consuming GM canola oil. The oil can be used as an ingredient in almost any packaged food.
Avoiding GM Foods
To avoid all genetically modified foods, consumers can choose USDA-certified organic foods, which are prohibited from using genetically modified ingredients. Another way to avoid GM foods is to avoid processed or packaged foods in general and choose more whole foods, such as fruits and vegetables.