Proteins play an essential role in many bodily functions including building organs, supporting the immune system, producing hormones, and promoting recovery and repairing tissues.
Of the 20 amino acids that make up proteins, nine cannot be produced by our body and must come from food. Of these, lysine is an amino acid that builds collagen, the most prevalent protein in our body that is vital for maintaining the health and integrity of blood vessels, strengthening bones, improving skin and joints, and optimizing the immune system and the healthy function of all organs. Other essential amino acids include methionine (aids in detoxification and the absorption of zinc and selenium), isoleucine (needed for the production of hemoglobin), phenylalanine, tryptophan and histidine (required for the production of neurotransmitters in the brain that regulate mood, appetite, and sleep), leucine and valine (important for muscle growth and tissue regeneration) and threonine (precursor of glycine).
Demands for proteins vary at different stages of our life.
Children and adolescents: Children who don't get enough protein may experience several health issues including fatigue, poor concentration, slowed growth, bone and joint pain, delayed wound healing and decreased immune response. Meeting daily protein intake goals is an essential part of child growth and development.
Adults: Depending on age, weight, and other factors, adults’ protein needs vary. For example, protein intake should increase in women who are pregnant or breastfeeding. Males typically require more protein in their diet than females. People who are sick, injured, or recovering from surgery also benefit from extra protein intake. Additionally, some health organizations recommend increased protein intake for athletes to promote muscle growth.
Protein-rich foods can help you feel full, which can reduce your calorie intake. Most adults need around 0.8 grams of protein per kilogram of body weight per day to prevent protein deficiency (on average, this is 45g for women, or 55g for men). This equates to approximately two portions of meat, fish, nuts or tofu per day.
Seniors: As we age, our muscles can feel weaker, which impairs our mobility and general health. Since nearly half of all proteins in the human body are present in muscles, maintaining a protein-rich diet and taking protein supplements are important. Unfortunately, this is not enough; to prevent muscle-loss in old age, it is crucial to keep a balanced and protein-rich diet, exercise regularly, and ensure adequate intake of micronutrients with additional protein supplementation.
How to recognize protein deficiency?
One of the most common signs that you're not getting enough protein is swelling (also called edema), especially in the abdomen, legs, feet, and hands. One possible explanation is that our blood proteins – albumin, in particular – help keep fluid from building up in our tissues. Additionally, frequently getting sick can often indicate a lack of protein which slows down the immune system. Mood changes or trouble thinking can relate to fluctuating blood sugar levels, but they can also indicate insufficient protein-mediated effects on the brain's neurotransmitters (which regulate mood). Muscle weakness can indicate a need for additional protein supplementation, as amino acids are essential for building muscle mass.
Therefore, maintaining a healthy diet, being physically active, and taking protein supplements as-needed can be your secret weapon to building strong muscles, preventing muscle-loss, and supporting your overall health at any age.