Protein is an essential nutrient and one of the main nutrients alongside carbohydrates, fats, vitamins, minerals, and water. It is imperative because protein helps build and maintain nearly every body cell and tissue. Protein is in muscles, bones, hair, nails, and skin. Your body uses protein from the food you eat to make specific protein molecules that have particular jobs. Some proteins work as enzymes (for digesting food), hormones (for regulating metabolism), antibodies (fighting infection), hemoglobin (for carrying oxygen in red blood cells), or neurotransmitters (chemicals that transfer information throughout brain and body).
Protein is made up of building blocks called amino acids. Your body makes some amino acids (non-essential amino acids) but the others must come from the food you consume (essential amino acids). Think of amino acids as the well-known ERECTOR set that assembles your life.
Amino acids get organized and form peptides or polypeptides. It is after these groupings that proteins are made. There is not just one type of amino acid, scientists have found numerous different amino acids in protein, but 22 of them are vital to human health. Of those 22, your body can only make 13 of them. The other 9 amino acids your body can’t make so must get them by eating protein-rich foods.
Types of Proteins:
- A protein that contains all 9 essential amino acids is called a COMPLETE protein. There are many foods that provide all 9 essential amino acids. Predominantly animal foods contain all 9 amino acids. Some soy and grain products contain all 9 as well. Animal sources include meat, poultry, eggs, milk, cheese, and pork. Plant based complete proteins include quinoa, tofu, edamame, tempeh, and soy products.
- A protein that lacks one or more of the essential amino acids is considered an INCOMPLETE protein. Incomplete proteins are found in plant foods which can be mixed together to make a complete protein. During the day, eat a variety of incomplete proteins from vegetarian foods such as nuts (i.e. sunflower seeds, almonds, pumpkin seeds,etc), legumes such as beans, peas and lentils, vegetables and grains (i.e. brown rice, buckwheat, spelt). The amino acids in these proteins conjoin to function as complete proteins for your body.
Because of the importance of making sure you get all your essential amino acids in each day, vegetarians need to pay special attention to their plant proteins and eating a variety to ensure they get in all 9 essential amino acids.
How Much Protein Do I Need?
The recommended dietary allowance (RDA) for protein is based on how much you weigh. The RDA is about 0.4 grams of protein for every pound of body weight.
Examples: A 120 lb. teenager needs 48 g. protein per day (120 lb. x 0.4 g./lb.)
A 160 lb. man needs 64 g. protein per day (160 lb. x 0.4 g./lb.)
Some individuals need more protein than the RDA. Growing children and teens, athletes, and dieters who are restricting their calorie intake may require up to two times the RDA.
Tracking Animal Food Sources:
Most teenagers don’t need any encouragement when meat arrives at their plate. Most foods in the teenage diet are their favorites. All kinds of meat and animal products contain a great amount of vitamins, minerals, and of course essential amino acids. However, in this world today we can’t overlook where our food sources are coming from and is it healthy for us and everyone? In the documentary Food INC, they take a look at our nation’s food supply and how it is controlled by a handful of corporations that often put profit ahead of consumer health, the livelihood of the American farmer, the safety of workers and our own environment. They look at the bigger-breasted chickens, the perfect pork chop, herbicide-resistant soybean seeds, even tomatoes that won’t go bad, but we also have new strains of E. coli—the harmful bacteria that causes illness for an estimated 73,000 Americans annually. Food, Inc. reveals surprising—and often shocking truths—about what we eat, how it’s produced, who we have become as a nation and where we are going from here.
Assignment #1 – Be a Protein Pro and Study Guide