Proteins are a vital component of every living cell. They are considered the building blocks of the body, since every body structure we have has a protein component in it. However, unlike carbs and fat, our body does not store protein. So in order for us to function, we need to eat protein-rich foods on a regular basis.
The recommended daily allowance for protein differs depending on your sex. Males ages 19 to 70 years old should consume 56 grams daily while women should take 46 grams per day. Failure to meet these requirements over a prolonged period can result in protein deficiency which can wreak havoc on our body functions. Here are 10 signs to watch out for, to know if you’re not getting enough protein. 
1. Decreased Immunity
Protein is important for our immune system. The white blood cells of our immune system (and the substances they subsequently produce) are also made up of protein. When we do not get enough protein, our body becomes immunosuppressed since the white blood cells cannot produce important molecules needed to form antibodies, interleukins, and cytokines – which fight off infections. 
2. Brittle Hair
Hair is made up of a protein called keratin. When our protein intake is inadequate, it compromises the structure of our hair. This makes it brittle and prone to damage. Another sign of protein deficiency is an unusual change in hair color. The pigment that gives our hair its color is also made up of protein. Changes in protein balance can cause these pigments to appear lighter than your usual hair color. 
3. Fluid Retention And Bloating
Albumin is a type of protein found in our blood. Without adequate protein, we would experience a decrease in serum albumin levels. This causes the fluids that are supposed to be inside the blood vessel to seep out into other body parts. This is the reason why people with protein deficiency experience edema. 
4. Muscle Fatigue
One of the biggest protein structures in our body is our muscular system. If you do not take in enough protein, it can cause your muscles to atrophy and you slowly begin to lose muscle mass. This makes your muscles weak, making normal activities painful and makes you more prone to fatigue.
Eating foods that are high in simple sugars and carbohydrates causes your blood sugar to spike and leads to the release of the hormone insulin. This causes you to feel tired and can eventually lead to eating more. On the other hand, protein takes more time for the body to digest. This is ideal since it slows down the release of insulin and helps keep your energy at a steady pace. Eating protein also helps you eat less since it takes longer for it to be digested; it makes you feel fuller longer.
6. Weak Nails
The nails are made up of keratin, the same type of protein found in hair. Similar to what was mentioned above, not eating enough protein can cause your nails to be brittle. Not only is this unsightly, it also makes you prone to nail fungal infections.
7. Impaired Sleep
The hormones necessary to produce a restful night’s sleep rely on protein for their structure. Without the protein, you’ll experience great difficulty trying to sleep. It’s a good thing that replacing the protein in the diet can drastically help normalize your sleeping habit. In one study published in the American Journal of Clinical Nutrition, it was found that eating a diet rich in protein greatly improves the sleeping pattern of the participants. 
8. Lack Of Concentration
Much like hormones, the neurotransmitters in our brain also require proteins to perform. Not getting enough protein can disrupt the delicate balance of neurotransmitters in the brain, leading to symptoms of brain fog – which include lack of concentration, irritability, and trouble learning.
9. Erratic Mood
Our moods are regulated by the neurotransmitters made by the body from the amino acids derived from protein. Without sufficient protein intake, we begin to experience mood swings, since it affects the levels of important neurotransmitters like norepinephrine and epinephrine.
10. Irregular Menstrual Cycles
The hormones and receptors that regulate the menstrual cycle (Estrogen, DHEA, progesterone) are also made from protein. When you don’t have enough protein in your diet, you begin to experience changes in your menstrual cycle.