Protein – The Basic Building Block of Food

Proteins are the basic building blocks of nature and essential to human life. They are made up of amino acids and part of every cell, tissue, and organ in our bodies. Next to water, protein is the most plentiful substance in your body.

Protein plays a key role in building and repairing body tissues, producing hormones and digestive enzymes, and transporting nutrients, oxygen, and waste throughout the body.

What is Protein?

There are 22 different amino acids that join together to make all types of protein. Amino acids are found in foods and can also be made by our bodies. Only certain amino acids, called nonessential amino acids, can be synthesized from the body. The body cannot make essential amino acids, so it is essential we obtain these through our diet.

Essential Amino Acids:

  • Histidine
  • Isoleucine
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine

Nonessential Amino Acids:

  • Alanine
  • Arginine
  • Asparagine
  • Aspartic Acid
  • Cysteine
  • Cystine
  • Glutamic Acid
  • Glycine
  • Hydroxyproline
  • Proline
  • Serine
  • Tyrosine


How much protein do I need?

Protein, along with carbohydrates and fat, is one of the three macronutrients in the human diet. Protein at each meal helps to fill you up, keep you satisfied, and maintain steady blood sugar levels. For the average adult, 0.8 grams of protein/kilogram of body weight is recommended. For example, a 150-pound person needs only 54 grams of protein per day. Average requirements range between 45-60 g/day.

Most adults in the United States eat way more protein than they need. Consuming too much protein can have harmful effects. Excess protein intake is taxing to the kidneys and limits calcium absorption.


What foods contain protein?

Protein provides four calories/gram. There are two main protein sources: animal and plant based.

Animal sources of protein contain all essential amino acids and are referred to as a complete protein.

  • Eggs
  • Dairy
  • Meat
  • Fish
  • Poultry

Plant sources of protein do not contain all essential amino acids and therefore are termed incomplete proteins.

It used to be thought that incomplete protein sources must be eaten with a complimentary protein that provided the missing amino acids in order to get the full spectrum of essential amino acids. We now know that this is not true. Research indicates that eating an assortment of plant proteins throughout the day will provide all essential amino acids for a healthy adult.

Many protein rich foods are also high in fat, such as animal sources of protein, and can lead to excess fat intake, which promotes obesity, cardiovascular disease, and cancer.

Consuming too little protein can also be harmful and affect the amount of protein your body can use for daily functioning and rebuilding. It is therefore important for vegetarians to know how much protein they are taking in since animal proteins are not part of the diet.

Instead of just focusing on your protein needs, aim to eat an healthy well-balanced diet that provides the protein you need as well as other health-promoting nutrients, such as essential vitamins and minerals.

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