Some signs and symptoms of protein deficiency include edema, hair loss, increased hunger, and more severe infections, among others.
Protein is one of the body’s main building blocks. It plays a key role in the structure and function of muscles, skin, enzymes, and hormones.
Protein deficiency is when your intake is unable to meet your body’s requirements.
While true protein deficiency is uncommon in the Western world, some people get very low amounts from their diet. This may affect almost all aspects of body function and lead to various health problems.
The most severe form of protein deficiency is known as kwashiorkor. It most often occurs in children in developing countries where malnutrition and imbalanced diets are more common.
Symptoms of protein deficiency may start to occur even when protein deficiency is marginal.
This article lists 8 symptoms of low protein intake or deficiency.
Edema is a condition characterized by swollen and puffy skin. This is a classic symptom of kwashiorkor.
Researchers suggest it may be caused by low amounts of human serum albumin, which is the most abundant protein in the liquid part of blood, or blood plasma.
One of albumin’s main functions is to maintain oncotic pressure — a force that draws fluid into the blood circulation.
In this way, albumin prevents excessive amounts of fluid from accumulating in tissues or other body compartments. Because of reduced human serum albumin levels, severe protein deficiency leads to lower oncotic pressure. As a result, fluid accumulates in tissues, causing swelling.
Remember that edema is a symptom of severe protein deficiency, which is unlikely to occur in developed countries.
Another symptom of kwashiorkor is fatty liver, or fat accumulation in liver cells.
Protein deficiency has been associated with fatty liver disease in developing countries. This condition may cause inflammation, liver scarring, and potentially liver failure.
It’s not clear why fatty liver disease occurs with protein deficiency, but research suggests it may be due to changes in the gut microbiome, mitochondria, and peroxisomal cells. This may lead to impaired synthesis of fat-transporting proteins, known as lipoproteins.
Protein deficiency may be associated with changes in the skin, hair, and nails, which are largely made of protein.
For instance, protein deficiency may affect hair growth and structure, which could lead to a hair loss condition known as telogen effluvium.
Kwashiorkor in children is also distinguished by flaky or splitting skin, redness, and patches of depigmented skin.
However, these symptoms are unlikely to appear unless you have a severe protein deficiency.
Your muscles are your body’s largest reservoir of protein.
When dietary protein is in short supply, the body tends to take protein from skeletal muscles to preserve more important tissues and body functions. As a result, a lack of protein could lead to muscle wasting over time.
Even moderate protein insufficiency may cause muscle wasting, especially in older adults.
In fact, research suggests adults ages 65 years and older should consume at least 0.5 grams (g) of protein per pound (lb) of body weight, which is more than the recommended daily allowance of 0.36 g.
Increased protein intake may help prevent sarcopenia, which is the slow loss of muscle associated with aging.
Not eating enough protein may weaken your bones and increase the risk of fractures.
A 2021 study found that participants who ate higher amounts of protein had up to 6% higher bone mineral density in their hips and spine than those who ate less protein.
After 5 years, the researchers found that those who ate more protein were less likely to experience bone fractures.
Researchers from the National Osteoporosis Foundation note that although protein may have some benefits for bone health, more research is needed to fully understand the link.
Insufficient protein intake may delay or prevent growth in children.
In fact, stunting is one of the most common signs of childhood malnutrition. In 2020, over 149 million children had stunted growth.
Children who don’t regularly consume enough protein may be four times more likely to have stunted growth.
A protein deficit may take a toll on your immune system.
For instance, eating enough protein is important to help build antibodies. These are produced by your white blood cells to help fight infections.
A 2013 study in male athletes who engaged in high intensity exercise found that participants who consumed a high protein diet experienced fewer upper respiratory tract infections than athletes consuming a low protein diet.
It’s important to note, however, that more research is needed to fully understand the link between protein deficiency and infections.
Protein plays a key role in appetite maintenance and total calorie intake.
If you’re not consuming enough protein, your body attempts to restore your protein status by increasing your appetite and encouraging you to find something to eat.
This may lead to consuming foods high in carbs and fat to compensate for the lack of protein, which is known as the protein leverage hypothesis.
However, foods high in carbs and fats aren’t as satiating high protein foods. Over time, this may lead to eating too many calories, causing unintended weight gain and obesity.
If you’re feeling hungry, try adding high protein foods to your diet.
The amount of protein you need to consume per day may depend on several factors, such as your age, level of physical activity, and fitness goals.
The Dietary Guidelines for Americans 2020 to 2025 recommends adult females consume 46 g and adult males 52 to 56 g of protein daily. On average, this equates to 0.36 g per lb (0.8 g per kilogram [kg]) of body weight.
However, research suggests this is the minimum requirement to prevent muscle loss and chronic conditions.
If you’re trying to gain muscle mass, the International Society of Sports Nutrition recommends eating 0.6 to 0.9 g per lb (1.4 to 2 g per kg) of body weight. The authors note that people who resistance train may also benefit from eating up to 1.3 g per lb (3 g per kg) of body weight.
Learn more about how much protein you should eat per day.
If your diet lacks protein, you may experience fatigue, hair loss, edema, and more severe infections.
Five signs of protein deficiency may include hair loss, dry skin, increased infections, increased hunger, and edema.
The best way to fix low protein levels is to eat foods high in protein, such as fatty fish, lean meats, eggs, lentils, legumes, nuts, and low fat dairy.
Several causes may lead to protein deficiency, including malnutrition, pregnancy, eating disorders, liver disorders, kidney problems, and inflammatory bowel diseases.
Protein is found everywhere in the body, including muscles, skin, hair, bones, and blood.
Protein deficiency is less common in Western societies, but it could present a wide range of symptoms. This may include edema, hair loss, and increased hunger, among others.
If you think you have protein deficiency, speak with a healthcare professional or registered dietitian. They could help develop a nutrition plan that’s right for you.