So what makes a protein a good protein? Unlike fats or carbohydrates, which can be good for you or bad for you based on their natural biochemistry, all dietary proteins are about equal. The quality of a protein mostly depends on how the food source is prepared or what fats naturally accompany the protein.
It may help to understand a little protein biochemistry first. Proteins are made of different combinations of 20 tiny building blocks called amino acids. Of those 20 amino acids, your body manufactures 11 of them. The other nine amino acids need to come directly from your diet, so they are called essential amino acids.
When you eat, your digestive system breaks down the proteins into the individual amino acids, absorbs, them and your body uses them to make new proteins that you need for muscles, organs and components of your immune system.
Complete and Incomplete Proteins
All proteins that come from animals are called complete proteins because they contain some combination of all nine essential amino acids. Plant-based foods, except soy, are called incomplete proteins because not all amino acids are present in each type of plant. Soy is actually a complete protein. If you eat meat, fish, poultry, eggs, dairy products or soy, you will easily get all the amino acids you need every day. If you are vegans, you need to eat a variety of plants to be sure you get all of the amino acids you need.Making Good Protein Choices
All animal products contain a large amount of protein and some plant foods such as legumes, nuts and seeds do as well. Fruits and vegetables generally don’t have as much protein, but they still contribute to your overall protein intake. Most of us only need 50 to 70 grams of protein every day, which is about what you would find in eight ounces of beef. It really isn’t difficult to get all of the protein you need each day -- the difficult part is choosing the healthiest protein sources.When you choose your proteins, you need to think about how the protein source is prepared or what fats are naturally found with that protein. Fish, like salmon or tuna, is a terrific protein source because the fats that accompany the proteins are high in omega-3 fatty acids, which are essential for good health and often deficient in western diets.
An example of a poor protein choice would be a chicken-fried steak. Steak, as a red meat, has a large amount of artery-clogging saturated fats and the style of cooking (breaded, fried and drenched in gravy) adds more unhealthy fats and extra calories.
Here are some tips for choosing healthy protein sources:
- Drink low- or non-fat milk, which provides plenty of calcium along with the protein.
- Roast, bake or grill meats, poultry and fish so that you don't need to add extra fats.
- Choose lean red meats to decrease the amount of saturated fats.
- Try a vegetarian main course once or twice a week.
- Don’t fry fish, it just adds extra fat and calories.
- Enjoy a handful of nuts as a snack –- nuts contain healthy fats as well as protein.
- Buy poultry and remove the skin and fat, or pick out a rotisserie chicken from the grocery store.
- Eating on the run? Choose a grilled chicken sandwich instead of a breaded chicken sandwich or greasy burger.
- Stay away from processed, high fat lunch meats, hot dogs and sausage.
Gropper SS, Smith JL, Groff JL. "Advanced Nutrition and Human Metabolism." Fourth Edition. Belmont, CA. Wadsworth Pub Co. 2005.
