A vegetarian diet can be healthy and provide sufficient nutrients if certain foods are eaten regularly. There are three main types of vegetarian diets - vegan, lacto-vegetarian, and lacto-ovo vegetarian. Vegetarians must obtain protein from sources like beans, lentils, nuts, dairy products and eggs. Iron, calcium, vitamin D and fatty acids can be obtained through foods like leafy greens, fortified foods, mushrooms and seeds. A balanced vegetarian diet includes fruits, vegetables, grains, proteins and healthy fats.