Most Americans have no trouble getting enough protein in their diets. Some milk or yogurt, an egg or two, a serving of beans or legumes and one or two servings of meat is, for most people, enough protein to make or exceed the recommended daily allowance (RDA) of 0.8 grams of protein per kilogram of body weight. If you're not getting enough protein, however, you may not notice it right away, because the effects can be subtle. When in doubt, talk with a doctor about your concerns before making any major changes to your diet or lifestyle.
Weakness or Fatigue
If you're generally getting enough sleep but still feel tired all the time or that you don't have enough energy to do the things you want to do, low protein intake could be a factor. Your body digests protein more slowly than carbohydrates, so eating enough of it helps maintain your energy level throughout the day and helps prevent blood sugar spikes or crashes. Protein is also responsible for building, repairing and maintaining lean muscle mass, so if your muscles feel consistently weak (as opposed to sore), you may need to take another look at your diet.
Protein also helps maintain a full head of healthy hair. If your hair seems to be thinning, growing very slowly and shedding onto everything, or if you can run your hand through your scalp, tug gently, and come away with more than a few hairs in your hand, you may want to check your protein intake.
How can it be that you just had a cold, but you're already getting another one? If constantly getting sick is the story of your life, you might need more protein in your diet. In addition to fueling muscle and bone health, protein boosts your immune system by maintaining a healthy T-cell count in the body. T-cells work to fight off germs, bacteria and viruses. The same is true for injuries, so if you get a scrape or a sprain and it's taking forever to heal, eating more protein may help.
Should You Worry?
Most Americans, especially those who eat meat, are getting enough protein. You're more likely to be deficient if you're vegan or vegetarian or if you're over age 50. According to a National Health and Nutrition Examination survey, more than one in three adults over age 50 don't get enough protein, and almost half of adults over age 70 don't get enough of the nutrient. To prevent muscle loss, protein needs increase as you age and may be nearly double the RDA for younger adults. If you have any health concerns related to your diet, talk with your doctor.