According to the National Institutes of Health (NIH), proteins are part of every cell, tissue, and organ in our bodies. These body proteins are constantly being broken down and replaced. The protein in the foods we eat is digested into amino acids that are later used to replace these proteins in our bodies. Protein is found in the following foods:
• Meats, poultry, and fish
• Legumes (dry beans and peas)
• Nuts and seeds
• Milk and milk products
• Grains, some vegetables, and some fruits (provide only small amounts of protein relative to other sources)
Proteins are made up of amino acids. Think of amino acids as the building blocks. There are 20 different amino acids that join together to make all types of protein. Some of these amino acids can't be made by our bodies, so these are known as essential amino acids. It's essential that our diet provide these. In the diet, protein sources are labeled according to how many of the essential amino acids they provide:
• A complete protein source is one that provides all of the essential amino acids. You may also hear these sources called high quality proteins. Animal-based foods; for example, meat, poultry, fish, milk, eggs, and cheese are considered complete protein sources.
• An incomplete protein source is one that is low in one or more of the essential amino acids. Complementary proteins are two or more incomplete protein sources that together provide adequate amounts of all the essential amino acids.
For example, according to the NIH, rice contains low amounts of certain essential amino acids; however, these same essential amino acids are found in greater amounts in dry beans. Similarly, dry beans contain lower amounts of other essential amino acids that can be found in larger amounts in rice. Together, these two foods can provide adequate amounts of all the essential amino acids the body needs. More information can be found at this site: http://www.cdc.gov/nutrition/everyone/basics/protein.html .
According to this website, http://www.healthaliciousness.com/articles/foods-highest-in-protein.php , while the body can manufacture several amino acids required for protein production, a set of essential amino acids needs to be obtained from animal and/or vegetable protein sources. Animal protein sources contain the complete set of essential amino acids, while all the essential amino acids can be obtained by eating a wide variety of plant foods. There is considerable debate over the amount of protein a person needs to consume per day, the current recommended daily intake (RDI) of protein is 46 grams for women aged 19-70 and 56 grams for men aged 19-70. Any excess protein consumed is turned into energy by the body, and it is controversial whether this excess protein causes a strain on the liver. A deficiency in protein leads to muscle atrophy, and impaired functioning of the human body in general.
Here are five tips for getting sufficient protein in your diet, according to the Harvard School of Public Health, found at this site http://www.hsph.harvard.edu/nutritionsource/protein/ :
1. Mix it up. Most reasonable diets provide enough protein for healthy people. Eating a variety of foods will ensure that you get all of the amino acids you need.
2. Go low on saturated fat. Beans, fish and poultry provide plenty of protein, without much saturated fat. Steer clear of fatty meats and use whole-milk dairy products sparingly.
3. Limit red meat—and avoid processed meat. Research suggests that people who eat even modest amounts of red meat have a higher risk of developing colon cancer, heart disease, and diabetes, and a higher risk of dying from heart disease, cancer, or any cause. There’s also substantial evidence that replacing red meat with fish, poultry, beans, or nuts, could help prevent heart disease and diabetes—and could lower the risk of early death. So make red meat (beef, pork, lamb) only an occasional part of your diet—no more than two 3-ounce servings a week—if you eat it at all. And skip the processed stuff—bacon, hot dogs, and deli meats—since that’s linked even more strongly to cancer, heart disease, and diabetes risk.
4. Eat soy in moderation. Tofu and other soy foods are an excellent red meat alternative. In some cultures, tofu and soy foods are a protein staple, and we don’t suggest any change. But if you haven’t grown up eating lots of soy, there’s no reason to go overboard: Two to 4 servings a week is a good target; eating more than that likely won’t offer any health benefits and we can’t be sure that there is no harm. And stay away from supplements that contain concentrated soy protein or extracts, such as isoflavones, as we just don’t know the long term effects.
5. Balance carbs and protein. Cutting back on highly processed carbohydrates and increasing protein improves levels of blood triglycerides and HDL, and so may reduce your chances of having a heart attack, stroke, or other form of cardiovascular disease. It may also make you feel full longer, and stave off hunger pangs.
It's important to eat the right amount and the right kind of protein to get the health benefits. Be mindful of the types of protein you consume as well as the amounts. There are protein supplements you can take, but talk with your doctor first before starting a regimen using those products or any other type of high protein diet. Sometimes, too much of a good thing is not good for you. As always, each person is different in their physical makeup. Your family doctor can help you design a good plan for your individual health needs, and you can be referred to a dietician if you have special needs. Protein is good, but be careful about your consumption.