Gluten-free mean absolute avoidance of all the proteins called glutens in wheat, barley, rye, spelt, kamut and some other grains by contamination (oats for example). Casein-free entails absolute avoidance of all mammalian dairy proteins (casein, whey for example) commonly found in milk products like cheese, milk, yoghurt, made from milks like goat, cow or sheep. Since the protein compositions are similar, some people who have to avoid dairy products also have to avoid soy products. For the purpose of this diet, dairy foods do not include eggs; only products made from mammalian milk.