How To Spot a Protein Deficiency — 13 Signs & Symptoms You Aren't Eating Enough

Do you eat enough protein? Protein is one of the most fundamental building blocks of your body — you use protein virtually everywhere. Your hair, bones, muscles, skin, and blood all need protein to take form.

When you aren’t getting enough protein in your diet, your body has different ways of letting you know. Keep reading to find out the 13 most common symptoms and signs of protein deficiency. (1)

protein-rich food products raw on table

When it comes to getting a healthy amount of protein, variety is the key. Eating a colorful range of proteins gives your body the nutrients you need for optimum wellness.

What is protein deficiency?

Protein deficiency definition: Protein deficiency is when you don’t get enough protein in your diet. Globally, an estimated 1 billion people suffer from protein deficiency, though most of the cases are in Central Africa and South Asia. In these countries, up to 30% of children aren’t getting enough protein. (2)(3)(4)

So what causes protein deficiency? Protein deficiency causes boil down to one thing — not ingesting enough protein daily to maintain normal body function. Though protein deficiency is quite uncommon in developed countries, some people are not hitting daily protein requirements. And over time, a protein-poor diet can trigger changes in the body such as muscle loss.

In severe cases, a protein deficiency disease called Kwashiorkor can happen. Kwashiorkor is a form of protein deficiency that often occurs in children found in developing countries plagued by famine. (5)(6)

13 signs and symptoms you’re not getting enough protein

What is the result of a dietary protein deficiency? There are specific signs of protein deficiency and symptoms to look for. Keep reading below to find out whether or not you may be experiencing any of the common protein deficiency or inadequacy symptoms outlined below.

1. Muscle loss

A loss of muscle mass is often one of the first signs of inadequate protein intake. This is because when the body is running low on dietary protein, it tends to take protein from our skeletal muscles. Over time, this leads to muscle wasting. (7)

It’s essential that you try and get the protein you need to build healthy muscle. (8)(9)(10)(11) Researchers have shown that upping your protein intake may help slow down muscle degeneration that happens with old age. (12)

2. Aches & pains

Are you feeling more sore and achy than usual after workouts? You probably aren’t eating as much protein as you should be. Muscle pains and achy joints are also some of the first signs of a protein deficit. (13)

banana slices next to banana protein shakes

Whey protein is a great and convenient source of protein you can take on the go and have right after a workout.

3. Unexplained hunger

Craving something sweet? When you aren’t getting an adequate amount of protein, your body tends to respond by actually feeling hungrier. And in general, the increase in hunger tends to revolve around sugar cravings. (14)

If you are feeling hungry throughout the day and have difficulties keeping your calorie intake in a normal range, try adding some lean protein to your meals.

4. Difficulty sleeping

Have trouble sleeping? It may have to do with how much protein you’re ingesting. Researchers have linked low protein intake (which is less than 16% of energy from protein) with difficulty falling asleep. (15)(16)(17)

Did you know?
Casein protein- which is derived from milk- is a slow-digesting protein. It’s especially great to ingest before bedtime because it keeps you stocked up while you’re sleeping, releasing into your body slower than other proteins. (60)

5. Easily fractured or broken bones

Have you fractured or broken a bone recently? Getting enough protein is essential to building up our bone density and strength. Studies have shown an inadequate protein intake has been linked to an increased risk of bone fractures. (18)(19)(20)

Did you know?
A study on postmenopausal women found that higher animal-based protein intake was associated with a lower risk of hip fractures. The highest intake was associated with a 69% reduced risk. (21)

6. Headaches

Can protein deficiency cause headaches? The answer is yes. Eating enough protein is essential to keeping migraines and headaches at bay. Studies have shown that headaches are a symptom of protein deficiency — and it’s a symptom that is more often seen in women than in men. (22)(23)

7. Thinning hair, brittle nails, and skin problems

Weak nails, hair, and skin problems are common symptoms of many micronutrient deficiencies. Not having enough protein long term could be rapidly aging your hair, nails, and skin. Biotin, which is found in protein-rich foods, is essential for naturally healthy hair, skin, and nails. (24)(25)(26)(27)(28)

8. Swelling

Notice any swelling in your feet, legs, hands, or abdomen? One of the most common signs that you’re extremely low on protein and may be suffering a deficiency is swelling. This swelling from a lack of protein in the diet is known as Edema. Experts say small amounts of protein in the bloodstream is what triggers the swelling condition. (29)(30)(31)(32)

Getting too much protein can also cause bloating. (33)

9. Fatigue

Feeling weaker and more fatigued than usual? It’s important to eat protein-rich foods to avoid fatigue and to fight fatigue naturally. (34)

If you’ve been lacking protein in your diet for a while, you have likely lost muscle mass, which in turn cuts your strength and makes you feel weak. It can also lead to anemia when your cells don’t get enough oxygen, which makes you tired. (35)

couple in the kitchen cooking

Do you love eggs and bacon? Studies have shown increasing your protein intake at breakfast will help keep your energy levels balanced throughout the day. (58)

10. Slower metabolism

Feel like your digestion system is moving slower than usual and you’ve gained weight because of it? It might be because you’re not eating enough protein. (36)

When you don’t get enough protein, your body loses muscle mass. In turn, your daily resting energy expenditure (REE) will go down because it is directly related to how much muscle mass you have. (37)

11. A compromised immune system

Feeling sick? A deficiency in the amino acids found in protein can increase your risk of infectious disease. Studies have shown a consistent lack of protein in the diet has been linked to a weaker immune system. (38)(39)(40)(41)

12. Mood swings and energy changes

Moody? A lack of protein can make you moody and also lead to diverse effects in your body’s energy balance. If you feel out of whack emotionally, it may have to do with your protein intake. (42)(43)

Did you know?
Pregnant women and new mothers are especially vulnerable to their protein intake affecting their moods and anxiety levels. (44)(45)

13. Slow healing injuries

Have any wounds that just don’t seem to be healing as fast as usual? This could have something to do with your protein levels. Studies have shown its essential to get the recommended daily minimum of protein to help heal and speed up sport-related injuries. (46)(47)

How much protein do you need?

The Recommended Daily Intake (RDI) for protein is 50 grams per day. However, some experts believe that this is too general and that many people should be eating significantly more than this. (61)

How much protein you should be eating is contingent on several factors, with two of the most important being your weight and lifestyle. It also depends on your age. For example, as men and women grow older, their daily protein requirements increase. (47)(48)(49)

There are a lot of different opinions on how much protein we should all be getting. Generally, a good rule of thumb is to aim to consume a minimum of 10% of your daily calories from protein and maximum have it be 35% of your total caloric intake. (50)(51)

The DRI (Dietary Reference Intake) is 0.8 grams of protein per kilogram of body weight or, around 0.36 grams per pound. This percentage adds up to:

  • Forty-six grams of protein daily for the average sedentary adult woman
  • Fifty-six grams of protein daily for the average sedentary adult man

If you workout often — chances are you need more.

woman at the gym lifting weights

If you’ve been training hard at the gym, have been coming home sore, but feel like you haven’t put on any muscle mass, you’re probably not eating enough protein.

How much protein do athletes need?

Do athletes really need more protein in their diet than everybody else? The answer is yes! During high frequency and intense training regimens, athletes should up their protein intake throughout the day and after workouts.

According to the Academy of Dietetics, Dietitians of Canada and the American College of Sports Medicine, athletes should consume 1.2.-2.0 grams of protein per kilogram of body weight daily. (50) Though you could need more. One study on endurance athletes found their protein intake should be increased by 50-100% over typical requirements. (54)

So who’s considered an athlete and should be eating athlete portions of protein? If you exercise with weights or bodyweight for more than one hour most days in a given week, you fall into the ‘athlete’ category for protein requirement. (52)(53)

To maximize your workout results, it can be extremely beneficial to work with a nutritionist. (55)

Is there a quick treatment for protein deficiency?

Feel like you’re running low on protein? Noticing some of the signs and symptoms we’ve outlined above? The first thing you should do is to eat some protein!

Most people can get the recommended amount of daily protein through food and without the use of protein supplements. But if you find it hard to eat right after a hard workout, protein powders and supplements are an excellent option for convenience.

What if you are a vegetarian or vegan?

You can get all the protein that you need from a plant-based diet. Though keep in mind studies have shown that vegetarians ⁠— especially vegans ⁠—need to make more of an effort than their carnivore counterparts at consuming an assortment of different fresh, plant-based proteins.

edamame in a white bowl

Protein isn’t just found in meat. You can also get plenty of protein from nuts and seeds. Edamame has a whopping 18.46 grams of protein per cup! (59)

Vegetarians need to focus on getting their amino acids by eating a variety of healthy, plant-based protein foods daily. If well-planned out, you can hit all your nutritional needs on a vegetarian or vegan diet — including your daily protein requirement. (56)(57)

The bottom line

While a true deficiency and experiencing all 13 of the negative effects of a deficiency is rare in developed countries, a consistently low protein intake over time can still lead to some of the symptoms listed above.

For optimal health, try to eat protein-rich foods every day.

Before you begin taking a protein powder or upping your protein intake over the recommended daily intake level— it doesn’t hurt to touch base with your practitioner or nutritionist. Having too much or too little protein has been shown to trigger adverse effects in the body. A healthcare provider can help you find the perfect balance.

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