The Power of Protein: Just the Facts

The adage “you are what you eat” is nowhere more fitting than when talking about protein. The protein molecules we ingest are literally the building blocks of our organs, bones and muscles.

Most people realize that protein is good for them in general, but many detailed questions remain: Does it matter what type of food I get my protein from? Does everyone need the same amount? Can I get too much?

Jeremy Greenhaus, RD, a clinical dietitian at The University of Vermont Medical Center, weighs in on this critical part of our diet.

Expert Q+A: Protein, Nutrition and Your Diet

1. Why is protein important?

Protein is important for our general health, for maintaining strength, and for keeping our organs healthy.

The building blocks of protein -- molecules called amino acids -- are used to create muscles and lean body mass. While our body can create some amino acids by itself, others – called “essential amino acids” – must be provided through our diet, and specifically, through the proteins in our diet.

2. How much is enough?

It depends on your weight, your age, and your activity level. For most healthy adults, the daily recommendation is 0.8 to 1 gram of protein per kilogram of body weight. Translated into everyday terms, a 154-pound adult would need 56 grams, or just shy of 8 ounces, of protein per day; that could be a hard-boiled egg for breakfast and a piece of chicken or fish at dinner. (You can visit MyPlate.gov for some additional ideas and examples of one-ounce protein servings.)

People who are very active or working out a lot, especially doing a lot of weightlifting or strength training, will want to aim for the higher end of the recommended daily protein amount. People over 65, too, should aim for the higher end.

Kids and adolescents have a higher protein-to-body-weight ratio (along the lines of 0.95 to 1.05 grams per kilogram of body weight) because their bones and their organs are still growing. Others who may need more protein include those who recently had a surgical procedure, are rehabbing from an injury, or are undergoing cancer treatment.

3. Should I eat more protein if I’m diabetic?

In general, yes. Protein can improve blood sugar control and help the body’s natural insulin response. Protein also sends the strongest signal to the brain of fullness. Anyone looking to control their weight, whether related to diabetes or not, may end up eating or snacking less if they eat more protein.

4. What are some good sources of protein?

The most complete proteins come from animal sources, like meat and fish. But I encourage people to limit their red meat intake to just once or twice per week because of its extra fat. Better to opt for leaner animal sources, such as poultry, fish or turkey.

5. How can I maximize my protein from vegetable sources?

I always recommend chili and lasagna, because it’s easy to cut the ground meat with protein-rich beans, legumes and lentils.

The problem with vegetable protein is that a serving of beans, legumes or rice by themselves will not provide the full range of amino acids our body needs. But by combining them, you get a complete protein. So try, for example, a piece of whole wheat toast with hummus. Or red beans and brown rice. There are lots of possible combinations to create complete proteins. This website has a good guide about plant proteins.

6. How do I know if I’m not getting enough protein?

Obvious symptoms include weight loss or anemia. Vegetarians and vegans have to be particularly careful of B-vitamin deficiency, which can cause fatigue, dry skin, brittle hair or brittle fingernails.

7. What happens if I eat too much?

If you’re healthy, getting too much protein won’t make much difference, because the excess will simply be broken down and stored, or excreted. (Though you could see some weight gain if the additional protein intake means you’re exceeding your recommended daily caloric limits.) People with kidney disease may need to limit their protein consumption, because processing of extra proteins can be hard on the kidneys.

8. Do you recommend supplements, powders or shakes?

Ideally, we like to see people get their recommended protein from whole food. But sometimes that’s not possible, such as when cancer treatments drastically reduce appetite, or when vegetarians or vegans have trouble meeting their daily protein needs. In those cases, protein supplements can be helpful.