When it comes to protein, be tend to think of meat. Meat can be expensive and some prefer not to eat it so soy becomes the alternative food. What a lot of people don't realize is that we don't need our protein to come from a single source. Complementary proteins are groups of foods that act as a full protein source when eaten together. One good pairing is beans and rice. These are both relatively cheap if purchased dry and can replace the meat in a meal saving a lot of money. Dairy and legumes also can serve as a protein source. The key is getting enough of the 8 essential amino acids. If your food combinations have all 8, you need not eat meat. One caveat is Vitamin B12 found in meats but not in a lot of partial protein sources.