Consequences of Protein Deficiency and Malnutrition

Doctor with sick patient
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Your body is a tapestry of thousands of different proteins. Your skin, muscles, organs and even your fat cells contain protein. Your dietary protein intake supports the formation and maintenance of all of these proteins. Protein deficiency and malnutrition can occur at any age due to illness or poor diet and may have devastating consequences on your health.

Muscle Wasting

Many of your body proteins have a short half-life, which means they are quickly used and degraded. This rapid turnover rate necessitates continuous protein production and an ongoing supply of new protein building blocks, or amino acids, from your diet. If you have a protein deficiency, your body breaks down its own proteins to harvest the amino acids needed to manufacture critical new proteins. Because your muscles contain a large amount of protein, they are a favorite site for amino acid harvesting. With chronic protein malnutrition, your muscles shrink -- a condition known as muscle wasting. Loss of muscle mass and fat leads to the characteristic "skin and bones" appearance of starvation.

Poor Wound Healing

When you sustain an injury, protein production in the area shifts into overdrive to replace the damaged tissue. With a protein deficiency, this process may be markedly slowed. A cut that would normally heal within a matter of days may persist for weeks. With a large injury, you may develop a chronic open wound, or skin ulcer.

Frequent Infections

Your immune system is particularly susceptible to the adverse effects of protein deficiency. Inadequate protein consumption can lead to a diminished immune system response and frequent infections. Your ability to recover from infections is also likely to be compromised if your diet lacks sufficient protein.


Protein deficiency disrupts the chemical balance in your body, which can lead to leakage of fluid into your body tissues, or edema. With mild edema, the swelling is most noticeable in your hands, feet and ankles. Your face and abdomen become involved with more severe edema. Protein deficiency accompanied by edema is called kwashiorkor and most commonly occurs in young children. Elderly people with a protein deficiency are also vulnerable to developing kwashiorkor.

Hair Breakage and Loss

Your hair is composed of a specialized protein called keratin. Protein malnutrition disrupts your hair growth. With a mild to moderate protein deficiency, you may notice your hair is brittle and breaks easily. Hair loss with noticeable thinning also commonly occurs. In most cases, your hair will regrow when you reestablish adequate protein intake.

Sexual and Reproductive Problems

Protein-deficiency malnutrition commonly leads to loss of sexual interest. Among women of childbearing age, protein deficiency may lead to irregular menstrual cycles or temporary loss of fertility. Protein malnutrition during pregnancy is dangerous for you and your baby. The risk of pregnancy-related complications increases if you are malnourished, and your baby is at high risk of not growing and developing normally.