Corn or maize is native to America but is now grown throughout the world. In grain form it is the staple diet for American Indians in Mexico, Peru and Southern North America. The Maori were given maize by American sailors which they grew and ate both fresh and fermented. The fermented corn was known as kaanga. Its strong smell didn't appeal to Pakeha who ate corn mainly as a grain. Eventually a sweet form was developed, and hence the name sweetcorn, it wasn't until the 1960's that sweetcorn became a really popular fresh vegetable. Several varieties are available including some with white kernels and others with a mix of yellow and white kernels. Varieties differ in sweetness. Recently the supersweet varieties have become popular, with Honey 'n' Pearl being the most widely grown. Sweetcorn is a very good source of fiber, protein and starch. corn is a great source of vitamin A, fiber, and other nutrients. Genetically modified (GM) foods are foods derived from genetically modified organisms. The DNA of genetically modified organisms has been modified through genetic engineering, unlike similar food organisms developed through the conventional genetic modification of selective breeding (plant breeding and animal breeding) or mutation breeding. GM foods were first put on the market in the early 1990s. Typically, genetically modified foods are transgenic plant products: soybean, corn, canola, and cotton seed oil, but animal products have been developed. For example, in 2006a pig engineered to produce omega-3 fatty acids through the expression of a roundworm gene was controversially produced. Researchers have also developed a genetically-modified breed of pigs that are able to absorb plant phosphorus more efficiently, and as a consequence the phosphorus content of their manure is reduced by as much as 60%. Critics have objected to GM foods on several grounds, including perceived safety issues, ecological concerns, and economic concerns raised by the fact that these organisms are subject to intellectual property law.