Protein is also a critical part of the processes that fuel your energy and carry oxygen throughout your body in your blood. It also helps make antibodies that fight off infections and illnesses and helps keep cells healthy and create new ones.
How Much Protein Do You Need?
Not getting enough protein in your diet can lead to health issues. For example, tissue can break down and lead to muscle loss.
But more isn’t necessarily better. While it can help build muscle, if you take in too much your body may store the excess as fat.
The Dietary Guidelines for Americans, put together by the U.S. Department of Agriculture and the U.S. Department of Health and Human Services, recommend the following daily amounts of protein for different age groups:
- Children under 4: 13 grams
- Children ages 4 to 8: 19 grams
- Children ages 9 to 13: 34 grams
- Women and girls ages 14 and over: 46 grams
- Boys ages 14 to 18: 52 grams
- Men ages 19 and over: 56 grams
Simply put, most everyone should get 10% to 35% of their calories each day in the form of protein. You need more calories for activities like biking, lifting weights, or running, but the percentage of protein remains in the same range.
After age 40, you can start to lose muscle mass, a condition known as sarcopenia, and you may need more protein.
If you’re overweight, you’ll need to lower your calorie intake. A dietitian can help you figure out how much protein you should have.
What Are the Best Sources of Protein?
High-quality sources of protein include:
- Lean beef or pork (in limited amounts)
- Dairy products
But you can get all the protein you need from plant-based sources. These include:
- Legumes, like beans, peas, or lentils
- Grains, like wheat, rice, or corn
You can combine large amounts of these with smaller portions of animal-based sources, like dairy products or eggs to make sure you're getting enough amino acids.
Limit the amount of protein you get from processed meats -- like bacon, sausage, or cold cuts.
How Do High-Protein Diets Affect You?
Some weight-loss programs, like the Atkins Diet and the Ketogenic Diet, call for high amounts of protein and fat while limiting carbs. But research shows that they seem to primarily work well only in the short-term. One reason may be that people aren’t able to stick with this type of eating plan over a long period of time.
Be mindful of what diets you try. Focusing just on protein and fat can keep you from getting all the nutrients you need, and that can lead to unhealthy side effects. That can lead to fatigue, dizziness, headaches, bad breath and constipation.