How Much Protein Do You Need Each Day?
The USDA suggests that you need about 15 to 20 percent of your daily calorie intake to come from proteins. If you need 2,000 calories per day, then about 300 to 400 calories should come from protein. One gram of protein has four calories, so that means you would need 100 grams of protein each day. One ounce of protein is about 28 grams, so you need about four ounces of protein each day. One cup of diced chicken breast meat has about 45 grams of protein, or just less than two ounces. Three ounces of canned tuna has 20 grams of protein, or about two-thirds of an ounce of protein.So how do you turn this into the right number of portions and portion sizes? For now, it is good to know that one serving of meat is usually about three ounces, or about the size of a deck of cards, and in general, three ounces of meat will have around 20 grams of protein. One cup of low-fat milk has about eight grams of protein. Twelve almonds have about three grams of protein.
Vegetarians and Incomplete Proteins
Remember the incomplete and complete proteins from the section on amino acids? Complete proteins contain all of the essential amino acids and incomplete proteins are missing one or more of the individual essential amino acids. Proteins from animal origin contain all of the essential amino acids, but proteins from plant sources do not. This means that a diet based on plant protein requires the right combinations of protein sources to get enough of all of the essential amino acids.People who regularly eat meat, dairy, and eggs don't need to be concerned with combining proteins since meat, eggs, fish, poultry and dairy products all contain complete proteins. Vegetarians and vegans may need to pay closer attention to the foods they eat to be sure they get a complete blend of amino acids by choosing complementary proteins. For example, grains are very low in the essential amino acid lysine, but legumes contain large amounts of lysine. When you eat both grains and legumes during the course of a day, you will consume all of the lysine you need. So grains and legumes are considered complementary.
Here are some combinations of complementary plant proteins that will provide you with all of the essential amino acids. The complementary proteins don't need to be combined at every meal as long as you get enough of the various proteins each day:
- Grains plus legumes. Try black beans and rice.
- Nuts and seeds plus legumes. Lentil soup with a serving of almonds on the side.
- Corn plus legumes. Try pinto beans in a corn tortilla.
- Try whole-grain pasta tossed with peas, almonds, and Low-Fat Vegan Alfredo Sauce.
- Whole wheat toast with peanut butter will give you a complete protein.
- Bean soup with whole grain crackers.
- Corn tortillas with refried beans and rice.
This Week's Assignment
There are various ways to get healthy protein into your diet, and I would like you to concentrate on making healthy choices for your protein needs. This means protein sources that aren't high in saturated fat or prepared in such a way that more fat and calories are added to the protein. At least three times this week, I would like you to substitute a healthy protein source for an unhealthy one. Here are some examples:- Choose lean sliced turkey for a sandwich instead of a hot dog or hamburger.
- Bake a fish fillet with some almonds and lemon instead of frying your fish.
- Spread some peanut, almond, or cashew butter on whole-grain toast for breakfast instead of eating sausage or bacon.
- Order a grilled chicken sandwich rather than a breaded deep-fried chicken sandwich.
- Try a vegetarian dish with legumes such as black, pinto, or navy beans.
This Week's Quiz
You can test your knowledge of proteins with this quiz: Quiz Four - Choosing Healthy ProteinsThis is lesson four of the basic nutrition - macronutrients e-course. Up next, lesson five is about fats. You may sign up for the whole e-course at Basic Nutrition - Macronutrients
Sources:
"Protein." Nutrition Source, Harvard School of Public Health. March 20, 2007.
"USDA National Nutrient Database for Standard Reference." USDA Agricultural Research Service. March 20, 2007.
"Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids." Institute of Medicine of the National Academies. September 05, 2002.
Gropper SS, Smith JL, Groff JL. "Advanced Nutrition and Human Metabolism." Fourth Edition. Belmont, CA. Wadsworth Pub Co. 2005.
