8 Symptoms of Protein Deficiency

Protein is a vital building block for our bodies.

And while you may know that foods like grilled chicken breast, salmon and hard-boiled eggs are a good source of protein, do you know if you’re getting enough protein from what you eat each day?

Daily protein requirements can vary from person to person thanks to factors like age, weight loss goals, muscle mass and activity level. (A good rule of thumb? Try to eat between 0.8 and 1 gram of protein for each kilogram of body weight each day.)

But what happens if you don’t eat enough protein? Could you have a protein deficiency?

Registered dietitian Natalie Romito, RD, LD, shares protein deficiency symptoms someone may experience.

Signs of a protein deficiency

Protein deficiencies are rare among people who live in the U.S., says Romito.

“It’s mostly tied to an inadequate overall food intake,” she explains. “Most of the people who end up with protein deficiencies may be dealing with a chronic condition that affects their appetite. Occasionally, it can be a picky eater or someone who doesn’t like typical high-protein foods and doesn’t know what to replace them with.”

And there’s not just one symptom that points to a protein deficiency or signs of low protein — you’ll more than likely experience several symptoms.

So, what should you look for? Here are the common symptoms of protein deficiencies.

Swelling

A protein deficiency can lead to kwashiorkor, a type of severe protein-energy undernutrition. That can lead to swelling, known as edema, which happens when your body’s tissues trap fluid. With kwashiorkor, you may notice swelling on both sides of your body (typically your hands and legs). This happens due to a lack of albumin, a substance that helps balance the fluids in your body.

“Swelling can be a sign that someone’s protein deficient,” says Romito. “But edema can be caused by so many things. If swelling is your only symptom, it’s not necessarily because your protein intake is too low.”

Stunted growth

If children aren’t getting enough protein, it may delay or prevent their growth and development.

“Proteins are the building block for muscle and bone. If you’re not getting enough, then your body has fewer resources to build these things,” explains Romito.

“If your child has been at a certain percentile on the growth chart, and then they drop to a lower percentile, that could be a sign that they’re not getting enough food overall or enough protein specifically.”

A weakened immune system

Your body needs protein to create antibodies, which attach to bacteria, fungi, viruses and toxins in an effort to remove them from your system.

“If you start getting sick more than usual and you have some other symptoms listed, then it might be more likely that your protein intake is inadequate,” says Romito.

And if you’re deficient in protein, there’s a good chance you’re also lacking other vital nutrients that keep you healthy. A shortage of overall nutrients may cause inflammation and oxidative stress, which also contribute to a weakened immune system.

Muscle loss

If you’re not getting enough protein, your body will turn to the protein stored in your muscles to use it for more important bodily functions.

“For people who have anorexia, it can even affect your heart muscle. That’s one of the biggest concerns for people who are severely undereating,” notes Romito. “The loss of that heart muscle can even lead to heart failure.”

Bone fractures

Calcium, vitamin D and protein are all needed to keep your bones strong and healthy.

“Collagen — the most plentiful protein in your body — is the main protein in bones,” shares Romito. “And it’s required in order for your bones to be strong and flexible.”

So, if your protein intake is dangerously low, you may be more likely to experience bone fractures.

Skin and hair changes

If you’re not getting enough protein, your skin and hair may be affected. Much like with muscle loss, your body starts prioritizing the protein it does have.

“If you’re not getting enough protein, your body doesn’t see your hair as essential compared to the brain and all these other systems your body needs to survive,” explains Romito. “Your body will delegate those resources differently.”

You may notice that your hair is brittle and breaks easily. Your skin may feel dry and look pale. Low protein may also cause telogen effluvium, or rapid hair loss.

Weight gain or weight loss

A protein deficiency may also impact how much you weigh.

“When it comes to weight loss, it’s likely due to an inadequate intake of protein and overall calories from not eating enough,” stresses Romito.

But you may also see an increase in your weight if your protein intake is too low.

“This happens because you start to lose muscle and your metabolism slows down,” she adds. “Then, if calorie intake returns to your normal baseline, you’re eating the same as you used to but gaining weight because your metabolism is now lower than it was due to the muscle loss.”

Anemia

Anemia happens when you have low levels of healthy red blood cells in your body.

“Proteins are needed to produce hemoglobin, the main component in red blood cells,” shares Romito. “Is a protein deficiency the main cause of anemia? Probably not. But if you’re not getting enough protein, it could show up on your bloodwork as being a little bit too low.”

Tips to get more protein

The best way to combat a protein deficiency? Work on getting more protein in your meals. Romito offers up the following advice:

• Include protein at every meal. Romito doesn’t recommend trying to cram all your protein into one meal. Instead, she says it’s best to split it up throughout the day. “If you get protein at every meal, it makes it easier to hit your total by the end of the day.”
• Consider plant-based sources of protein. While you may tend to think of animal sources for your protein needs, Romito says adding plant-based protein sources to the mix can help. Options include edamame, tofu, beans and lentils, which are high in protein. “It usually takes a little bit more intention to make sure you hit your protein needs when you’re eating fully plant-based.”
• Don’t rely solely on protein shakes. You want to be mindful of how often or how heavily you use protein shakes or protein bars. “Getting whole food sources of protein is best. But if it’s the difference between meeting your protein needs and not meeting your protein needs, that’s where the protein shakes and bars can help fill in the gaps,” says Romito.

Bottom line?

While protein deficiencies aren’t very common in the U.S., you may need some overall help meeting your daily protein needs — especially if you notice a shift in the kinds of foods you’re eating.

“If you have a change in your appetite that’s affecting your desire to eat or if you’re craving high-protein foods, I would discuss it with your healthcare provider,” says Romito.

“They can make recommendations and share resources. They can also provide insight into any medical conditions that may be contributing to your shift in eating. And they may suggest working with a registered dietitian to ensure you’re getting enough protein throughout your diet.”