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.
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.
1. Swelling
One of the most common signs that you’re not getting enough protein is swelling (also called edema), especially in your abdomen, legs, feet, and hands. A possible explanation: The proteins that circulate in your blood — albumin, in particular — help keep fluid from building up in your tissues. But many things can cause edema, so be sure to check with your doctor in case it’s more serious.
2. Fatty liver
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.
4. Loss of muscle mass
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.
6. Stunted growth in children
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.
7. Increased severity of infections
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.
8. Greater appetite and calorie intake
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.
