There are many different reasons that you might choose to become a vegetarian for. For some, vegetarian diets are a political choice, or a statement of their ethical beliefs. Others choose to eat only vegetarian food because of religious beliefs. Still others choose a vegetarian lifestyle for health reasons. For many, the reasons to be vegetarian are more complex - they may intertwine the belief that vegetarian diets are better for the Earth with a morality that rejects killing living things for food, for instance. The one thing that every vegetarian has in common with every other human is a need for the right balance of nutrients in their diet.
For decades, doctors warned: those who ate vegetarian diets were depriving their bodies of essential proteins and amino acids by avoiding meat and animal products. Animal proteins, the traditional wisdom claimed, are superior to those derived from plant sources, because they are 'complete' proteins. Therefore, the body had to do less work in order to make use of the amino acids and other nutrients in animal proteins.
To counteract that, scientists and nutritionists put forth a theory called 'protein complementarity' - how to prepare vegetarian food to provide all the amino acids needed to make a complete protein at one meal. This theory was introduced to the public at large by Frances Moore Lappe' in her landmark book, Diet for a Small Planet. According to this theory of vegetarian eating, you needed to include all the ingredients of a complete protein at one sitting in order to get the benefits of that protein. A whole wheat peanut butter and a banana sandwich with a glass of milk, for example, provided all the ingredients to make a complete protein. It seemed incredibly complex - and doctors warned that most people who chose to be vegetarian were putting their health at risk.
In the years since the publication of Diet for a Small Planet which introduced the concept of vegetarian protein complementarity to the general public, scientists have learned a great deal about nutrition, and particularly about amino acids and proteins. They know now that it's actually MORE difficult for the human body to make use of many animal proteins. More importantly to those who choose to be vegetarian, scientists now understand that it's not important to nutritionally balance every single meal. Instead, the aim of people eating exclusively vegetarian food should be to include a wide variety of grains, legumes, nuts, seeds, vegetables and fruits in their diet over the course of a few days.
One of the easiest ways for a vegetarian to be sure he's getting all the amino acids and essential nutrients that his body needs is to color code his meals. Green leafy vegetables provide different nutrients than dark orange vegetables, and blue/purple fruits and berries provide yet another set of essential nutrients. A salad of dark green romaine lettuce with red tomatoes, brown olives, orange carrots and a sprinkle of sunflower seeds can provide most of the nutrients that your body needs for the day. Eat colorfully for the best benefits of your vegetarian diet.