[Photo: Kenyans examining insect-resistant transgenic Bt corn] Genetically modified (GM) foods, more accurately called genetically engineered foods, are foods that have had their DNA altered through genetic engineering. Unlike conventional genetic modification that is carried out through conventional breeding and that have been consumed for thousands of years, GE foods were first put on the market in the early 1990s. The most common modified foods are derived from plants: soybean, corn, canola, and cotton seed oil. Controversies surrounding GM foods and crops commonly focus on human and environmental safety, labeling and consumer choice, intellectual property rights, ethics, food security, poverty reduction, and environmental conservation.