Importance of Protein in the Diet
What is Protein and What is the Importance of It?
Protein is one of the three macronutrients of the diet along with fat and carbohydrates needed for overall growth and development of the human body. Not one macronutrient is of greater importance than the others, each macronutrient needing a balance of the other macronutrients to properly complete its function. Protein consumption is specifically important for the building and maintaining muscle tissues. A sufficient intake of protein in the diet is not the only component involved in muscle building, individuals must also partake in resistance exercises such as yoga, barre, Pilates or any form or weightlifting. When individuals are consuming adequate protein to meet their needs based on their size and the amount of activity, they are taking part in, the client will be in what we call a “positive nitrogen balance”. Adequate protein intake is not just crucial for muscle growth, but it is also key for the function of various enzymes, hormones, and proteins such as structural, transport and immune system proteins.
How is Protein Broken Down and Utilized in the Body?
Protein is made up of amino acids, which are nitrogen-containing components. Amino acids can be used as a energy source for the body but lipids (or fat) and carbohydrates are more readily utilized as fuel. When we eat protein-containing foods, the proteins are broken down into their amino acid form through the processes of digestion in the body. Once absorbed, these amino acids are transported to the liver. The proteins in the body are constantly being anabolized and catabolized, meaning build up and broken down on a regular basis. A person’s dietary intake of protein and the body proteins that are being broken down provide the amino acids needed for protein synthesis.
Individuals who are classified as athletes would need increased amounts of protein sources in their diet compared to the average person. The recommended intake for the average individual is 0.8-1.0g/kg of body weight and 1.2-2.0g/kg of body weight for athletes depending on their sport and level of activity. Patients in hospitals that are critically ill need higher protein diets, and the recommended amount would be ~1.2-2.0g/kg depending on their specific illness and any previous underlying conditions.
Different Types of Proteins
Protein can be found in both plant and animal-based sources. These protein sources differ in amounts of protein being provided and types of amino acids being supplied. Animal-based protein sources are considered complete protein sources and plant-based protein sources are considered incomplete.
Incomplete vs. Complete Protein Sources
The body can make 13 of 22 amino acids on its own. These are called non-essential amino acids. The remaining 9 amino acids are the essential amino acids, the ones that the body cannot make must be obtained through dietary intake. The issue that arises when choosing plant-based protein sources over animal-based sources is that not all plant-based sources contain all the 9 essential amino acids that our bodies need. But you are in luck, it is easy to combine protein sources to get the nutrients your body needs! Combining a grain source such as bread, pita, rice, oats, etc. with a nut butter, bean or lentil, or hummus can result in a complete protein source.
Plant-based protein sources are nuts (cashews, almonds, peanuts, macadamia nuts, brazil nuts etc.), nut butters, seeds (pepitas, sunflower seeds, chia seed, flax seed, hemp seeds, etc.), tofu, soy protein, tempeh, beans (black beans, chickpeas, Romano beans, kidney beans, lentils, etc.), edamame, spinach, broccoli, quinoa, and buckwheat among others.
Animal-based protein sources are complete protein sources featuring all 9 of the essential amino acids that the body needs. Some examples of animal-based protein sources include poultry (chicken or turkey), fish (salmon, white fishes, tuna, trout, etc.), beef, eggs, cheese, milk, Greek yogurt, pork, seafood (shrimp, lobster, etc.).
Protein supplements are common amongst your everyday gymgoers as well as various types of athletes. There are powders, bars, and premixed beverages that are full of protein and are market to those needing increase protein intake for their sports or to build and sustain increase muscle mass. They are generally more expensive but are probably the most easy and portable source of protein. Protein powders are typically made of whey protein, casein protein, egg protein, pea protein, hemp protein, brown rice protein, or a mix of a few of these types of protein powders. Whey protein is best used for muscle gain and casein, or a combination of whey and casein are best used for weight loss or as a meal replacement. As casein and whey are by-products of cheese production, they are considered animal-based protein sources and therefore vegans and vegetarians may be more inclined to use brown rice, hemp, or pea protein products.
Important Things to Note
When individuals are meeting their calorie needs it is likely that they are consuming protein above their recommended protein needs. If protein is being consumed in excess and the individual is not doing high level activities or workouts than the protein will be stored as fat. This is where working with a registered dietitian or working with a local Calgary meal prep company like Nutrimeals can come in handy. We will handle the calculations of your calorie and macronutrient needs (protein, lipid, & fat) as well as the prepping of the food that will meet your required needs. As the in-house dietitian here at Nutrimeals I will work with you to meet your goals whether that be to lose weight, gain muscle, or to get back on track with your health!
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Dunford, M. A., & Doyle, J. A. (2008). Nutrition for sport and exercise. Belmont, CA: Thomson Wadsworth.