Why do I need protein in my diet?

Dr. Andrea Pennington, MD
Integrative Medicine
Proteins are made up of amino acids and are essential for growth and repair in the body. They are the building blocks of muscles, enzymes and some hormones. A gram of protein contains four calories.
Proteins are composed of molecules called amino acids, which, when joined in different combinations, make up most of the tissues in our bodies: muscles, organs, skin, nails, and hair, for example. They also make up many of the biochemicals, like enzymes and hormones, which help our bodies grow, heal, digest, and detoxify. There are twenty-three amino acids in the human body, nine of which are essential. Animal sources of protein -- such as eggs, dairy products, and meat -- contain all nine essential amino acids. Plant sources of proteins -- such as beans, nuts, and seeds -- lack some of the essential amino acids.

Individual needs for protein can vary greatly depending on age, activity level, genetics, or chronic/acute illness. Those of us who do not meet our bodies' need for protein through our diet can experience symptoms of protein deficiency, which include: weakness, poor muscle tone, fatigue, dry and brittle hair and nails, slow wound healing, weakened immune system, blood sugar imbalances, and even depression.

Your body uses the protein you eat in a variety of ways, including:

  • Build and repair all tissues
  • Form enzymes and hormones
  • Form antibodies to fight infection
There are plenty of ways to add protein to your diet, including plant-based protein options for vegetarians and vegans. Protein is found in meat, fish, poultry, eggs, dairy products, dried beans, peas, peanut butter, nuts and seeds.
Dr. Mehmet Oz, MD
Cardiology (Cardiovascular Disease)
Protein is essential for several bodily functions. In fact, it accounts for 20% of our body weight and helps us synthesize enzymes, hormones and important cellular structures. It also helps us with fluid balance and with building antibodies that guard against infection. Without proper protein we wouldn’t survive.

Protein also helps us feel full after a meal. People who don’t eat enough protein may actually eat more food and still have an appetite afterwards.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.