Genetically modified foods have been altered in some way, usually for the purpose of increasing yield or efficiency. This is common in agricultural crops, especially in corn, grains, and various fruits and vegetables. Common reasons for genetic modification include improving flavor, increasing resistance to insects, and increasing the yield. Though agricultural crops are the most commonly modified foods, animal products are sometimes altered as well. For example, synthetic growth hormones are used to make beef cows bigger, yielding more meat, and to increase the amount of milk that dairy cows can produce. Some of these practices are criticized by various groups as being unsafe or unnatural. Despite this, an estimated 75% of all foods purchased in America contain at least some genetically modified ingredients.
and of course these companies are do not include GMO on the title.