Protein
Summary
Protein (WatSol) [DV ~ 120g] {Half Life = 10 Hours} Needed to build and repair muscles, allows metabolic reactions to take place, produces hormones such as insulin and oxytocin, stimulates antibody production, and helps you feel fuller for longer. Too little protein can cause muscle wasting, bone fractures, skin, hair and nail problems, fatty liver and an increased risk of infection. Increasing protein intake directly increases muscle mass with or without exercise, and increases longevity.
Proteins are large, complex molecules made up of amino acids and are crucial for the structure, function, and regulation of the body's tissues and organs. They are one of the three macronutrients, along with carbohydrates and fats, essential for human health (Szalay & McKelvie, 2021).
Amino Acids: Proteins are composed of 20 different amino acids, which are organic compounds made of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur. These amino acids are classified into three categories:
Essential Amino Acids: Cannot be synthesized by the body and must be obtained through diet (e.g., leucine, lysine, methionine).
Non-Essential Amino Acids: Can be synthesized by the body (e.g., alanine, aspartic acid).
Conditionally Essential Amino Acids: Normally non-essential but become essential under certain conditions (e.g., arginine, glutamine).
Functions of Protein:
Structural Support: Proteins like collagen and keratin form the structural framework of cells and tissues.
Enzymatic Activity: Enzymes, which are proteins, catalyze biochemical reactions necessary for digestion, energy production, and other metabolic processes.
Transport and Storage: Hemoglobin, a protein, transports oxygen in the blood, while ferritin stores iron.
Immune Function: Antibodies are proteins that help the body fight off infections.
Movement: Actin and myosin proteins are involved in muscle contraction and movement.
Hormonal Regulation: Some hormones, such as insulin, are proteins that regulate various physiological processes.
Protein Sources: Proteins are found in both animal and plant foods.
Animal Sources: Meat, poultry, fish, eggs, dairy products. These are complete proteins, meaning they contain all essential amino acids.
Plant Sources: Beans, lentils, nuts, seeds, tofu, quinoa. Some plant proteins are incomplete, lacking one or more essential amino acids, but a varied diet can ensure all essential amino acids are consumed.
Recommended Dietary Allowance (RDA): The RDA for protein depends on age, sex, and level of physical activity. For the average adult, it is approximately 0.8 grams of protein per kilogram of body weight. Athletes and those with higher physical demands may require more (Rush, 2023).
Protein Deficiency: Lack of adequate protein intake can lead to health issues such as muscle wasting, weakened immune system, and growth retardation in children. Severe protein deficiency leads to conditions like kwashiorkor and marasmus (Healthdirect Australia, 2023).
Excessive Protein Intake: While high-protein diets can be beneficial for muscle building and weight management, excessive intake may lead to health problems like kidney damage in individuals with pre-existing conditions, dehydration, and loss of calcium.
Protein and Health:
Weight Management: Protein can aid in weight loss by promoting satiety and preserving lean muscle mass.
Muscle Growth: Adequate protein intake is essential for muscle repair and growth, especially after exercise.
Aging: Protein needs may increase with age to prevent muscle loss (sarcopenia) and maintain overall health.
High Protein Foods (from highest to lowest)
Nutritional Yeast [Non-Fortified] (54g)
Parmesan (38g)
Venison (36.1g)
Turkey (29g)
Tuna [Skipjack] (28g)
Chicken [Pasture Raised] (27g)
Pork (27g)
Beef [Grass Fed] (26g)
Halibut (22g)
Almonds (21g)
Pistachios (20g)
Salmon [Wild Caught] (20g)
Chickpeas (19g)
Oats (17g)
Walnuts (15g)
Wholegrain Pasta (14g)
Eggs [Pasture Raised] (13g)
Greek Yoghurt (10g)
Lentils (9g)
Black Beans [Cooked] (9g)
Sourdough Bread (7.9g)
Garlic (6g)
Potato Skin (6g)
Sun-dried Tomatoes (5g)
Peas (5g)
Quinoa (4g)
Broccoli (4g)
Corn (3g)
Whole Milk [Grass Fed] (3g)
Mushrooms (3g)
Reference
Department of Health & Human Services. (n.d.). Protein. Better Health Channel. https://www.betterhealth.vic.gov.au/health/healthyliving/protein#:~:text=Proteins%20are%20made%20up%20of,following%20the%20Australian%20Dietary%20Guidelines.
Healthdirect Australia. (2023, October 12). Protein. Healthdirect. https://www.healthdirect.gov.au/protein
Restivo, J. (2023, December 1). High-protein foods: The best protein sources to include in a healthy diet. Harvard Health. https://www.health.harvard.edu/nutrition/high-protein-foods-the-best-protein-sources-to-include-in-a-healthy-diet
Rush, T. (2023, June 5). Protein intake — How much protein should you eat per day? Healthline. https://www.healthline.com/nutrition/how-much-protein-per-day
Szalay, J., & McKelvie, C. (2021, November 15). What is protein? livescience.com. https://www.livescience.com/53044-protein.html