Protein is an important macronutrient that plays a major role in the entire body. It makes hormones and enzymes, while also helping keep your muscles, bones, blood, and hair and nails healthy.

Protein helps build, repair and maintain tissues, as well as boost the immune system, increase fat burning and lower the risk for diabetes.

*Related: 8 Protein Supplements That Actually Work

Lack of protein may result in a protein deficiency. If you are having difficulty sleeping, losing weight, suffering from frequent headaches, or craving sugar, you may need to add more protein to your diet.

If you have noticed the number on the scale going down, this may be a sign that you are protein deficient. Lack of protein may cause your body to breakdown your muscles, ultimately resulting in weight loss.

Your hair is made up of protein, it needs it to stay healthy. Therefore, without an essential amount being consumed you may notice your hair thinning or falling out.

See: 10 Foods for Healthy Hair and Skin

Craving sweets is one of the first signs that your body needs more protein. It helps keep your blood sugar steady; therefore, lack of protein sends your glucose levels all over the place causing you to crave a quick fix like candy.

Difficulty sleeping and insomnia are common among people suffering from protein deficiency. This may also be due to a serotonin deficiency, which is caused by a lack of certain amino acids, Lovetoknow explains. “These amino acids are produced when protein is broken down, and a diet with insufficient protein could lead to difficulty in sleeping.”

Protein deficiency may cause anemia and low blood sugar, which ultimately leads to headaches. A few natural remedies for headaches include chamomile tea, peppermint oil and magnesium.

See: 10 Things That Happen to Your Body When You Have a Headache

Weak nails or white streaks spanning the nail are commonly caused by a protein or zinc deficiency. When the nails lack the proper blow flow or nutrients needed an interruption in growth occurs.

Protein is essential for building strong muscles; therefore, without it your muscles will become small and weak overtime. You may begin to notice a change in your strength, especially when exercising.

If you used to be muscular and strong, but now you’re feeling weak and in pain, this is a strong indication that you have a protein deficiency.

See: The 9 Best Products to Relieve Muscle Soreness

Protein diets have been shown to rev up the metabolism. It helps increase your muscle mass, ultimately resulting in a jump started metabolism and improved caloric burn.

Your immune system is made up of proteins; it needs new protein synthesis to function. If you don’t get enough of it, your immune system will weaken. Adult women should consume 49g of protein daily and adult men should consume 56g.