Low protein intake

How Much Do You Need?

A minimum intake of protein per day should be 10% of total caloric intake while a maximum one should be 35% (0.36* body weight in pounds). You should consume a variety of protein sources throughout your day at three main meals and even on snacks.

Swelling:

The most common symptom of protein deficiency is edema or swelling where it appears especially in your abdomen, legs, feet, and hands. A possible reason is the protein albumin in blood circulation the keeps water up, many factors are behind edema don’t forget to check your doctor.

Mood Changes:

Mood changes can be due to lack of neurotransmitters due to protein deficiency because amino acid is the building block of them. With low levels of dopamine and serotonin, for example, you may feel depressed or overly aggressive.

Hair, Nail, and Skin Problems:

These are made up of proteins like elastin, collagen, and keratin. When your body can't make them, you could have brittle or thinning hair, dry and flaky skin, and deep ridges on your fingernails. Your diet isn't the only possible cause, of course, but it's something to consider.

Weakness and Fatigue:

Slower metabolism, loss of muscles and other factor cause weakness and fatigue especially if you are 55 years old. It can also lead to anemia when your cells don't get enough oxygen, which makes you tired.

Hunger:

Protein fills you up and helps you to delay meals. Low protein intake may cause hunger and loss of satiety feeling.

Slow-Healing Injuries:

People who have cuts or injuries may have a longer healing process due to lack of protein and collagen too which it's found in connective tissues as well as your skin. To make blood clot, you need proteins, too.

Getting or Staying Sick:

Amino acid boosts immunity by producing antibodies that make white blood cells to defend bacteria and viruses. Protein is needed for absorption and digestion of nutrients. There's also evidence that protein can change the levels of disease-fighting "good" bacteria in your gut.

Who Might Come Up Short?

Elderly people and people with cancer may have trouble eating as much protein as they need. Severe malnutrition from lack of protein is called kwashiorkor. It's more common in developing countries, especially with children, or after a natural disaster.

Athletes:

If you are exercising and on a well-balanced diet you are taking enough protein; for athletes who are on strenuous type exercise they need double amount of protein compared to an average person. 0.5-1 grams per pound is an easy way for getting enough protein.

Sources:

https://www.webmd.com/diet/ss/slideshow-not-enough-protein-signs

https://www.shape.com/healthy-eating/diet-tips/high-protein-foods