In this article, we’ll be covering the basics of protein. After reading this, you should have a better idea of how much protein you need to build muscle or maintain while trying to lose weight. We’ll also break down the different types of protein, including animal and plant proteins.
Are you trying to build some muscle but need to figure out how much protein you should eat? We’ll cover the basics of protein, how much protein you should eat to build muscle, and the different types of protein. After reading this, you’ll be able to figure out how much protein you should eat each day to support muscle growth and the most effective way to split this up throughout your day.
What is Protein?
Protein is one of the three macronutrients; it’s an essential nutrient our body needs in large quantities to survive. As a fuel source for our body, protein provides four calories per gram consumed. Our bodies use proteins to form muscle tissue, hormones, and antibodies in our immune system. Proteins are chains of peptides; these peptides are made up of amino acids. Twenty common amino acids make up protein; 9 are essential, and 11 are non-essential. The essential amino acids are essential because our bodies can’t make them on our own, and we need them to survive.
The Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kg of body weight.[1] For a 160 lb. person (72.7 kg), this would equal 58.2 g. per day. It’s important to remember that the RDA is a recommendation to sufficiently meet the basic nutrient requirements of 97% of healthy adults. This is a recommendation of the average nutrient intake needed for survival, not optimal performance or muscle growth. For instance, moderate exercise, like 1 hour on a treadmill at an intensity of 55% VO2 Max stimulates whole body muscle protein breakdown by 25% in a healthy adult.[2] This would bump up someone’s daily required protein intake to greater than 1 g per kg bodyweight.
Protein Quality
High-quality protein consumption optimizes whole-body protein metabolism, including skeletal muscle mass.[3] Some ways to evaluate the quality of a protein include rating its completeness (if it contains all 20 amino acids), its rate of digestion (some proteins like casein are digested slowly while others like whey are digested rapidly, soy and egg are more intermediate), and it’s overall metabolism.
In 1989, joint experts from the FAO and WHO developed a system to rate the quality of proteins. This is known as the Protein Digestability Corrected Amino Acid Score or PDCAAS. The PDCAAS tests the amino acid content of protein sources to that of a reference protein that contains an indispensable amount of amino acids to compute a score. A PDCAAS score of 1 indicates that a protein is complete, while a score below 1 indicates that the protein is sub-optimal. In general, animal-based protein sources like whey, casein, milk, eggs, and beef have scores of 1. For reference, soy protein also has a score of 1, while peas and quinoa have at least 0.75.[4]
Dietary Sources of Protein
Some familiar dietary sources of protein include
Beef
Chicken
Turkey
Pork
Tilapia
Salmon
Anchovies
Tuna
Trout
Sardines
Flounder
Shrimp
Lobster
Crab
Eggs
Milk
Whey
Casein
Greek Yoghurt
Cottage Cheese
Kefir
Soy
Kidney Beans
Chickpeas
Mung Beans
Black Beans
Lentils
Peas
Red Kidney Beans
Corn
Rice
Quinoa
Amaranth
Almonds
Pistachios
Cashews
Peanuts
Pumpkin Seeds
Sunflower Seeds
Hemp Seeds
How Much Protein Do You Need to Build Muscle?
When building muscle, it’s important to remember that our body constantly shifts between breaking down and building muscle. To maintain muscle, we need a net protein balance of zero; if we want to build muscle, protein synthesis has to exceed the rate of protein breakdown.[5]
In a joint recommendation, the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine recommended a protein intake of 1.2-2.0 g/kg/d. While the International Society for Sports Nutrition recommended a protein intake of 1.4-2.0 g/kg/d for physically active individuals.[6] If a 160 lb person were to consume protein within this intake range, they’d be eating between 87-145 g of protein per day.
Research on this topic indicates that for strength-trained athletes, lean mass growth is maximized at a protein intake of around 1.6 g/kg/day. With best practice for stimulating muscle protein synthesis indicates repeated ingestions of a moderate dose of high-quality protein (about every 3 hours) throughout the day.[7] To maximize protein synthesis, this protein serving amount per meal would be between 0.25-0.55 g per kg; for most people, this would mean a serving of about 20-40 g protein per meal.[8,9]
Protein and Weight Loss
In addition to supporting muscle growth, protein intake positively affects body composition in general. Some research shows an inverse association between the intake of animal and plant proteins and waist circumference, body weight, and body mass index (BMI).[10] The data for weight loss diets shows beneficial effects for appetite, body weight management, and health outcomes in diets with daily protein intakes of 1.2-1.6 g/kg/day or about 25-30 g of protein per meal.[11] Higher protein intakes during weight loss diets are essential for several reasons, one of the main ones being the preservation of lean muscle mass.
Animal vs. Plant Proteins
We can consume protein from both animal and plant proteins. Plant-based protein sources are generally less effective at stimulating muscle protein synthesis than animal-based proteins. This is likely due to lower levels of essential amino acids, limited amounts of specific essential amino acids, or lower levels of leucine content per serving in plant-based proteins.[12] In one study, researchers compared the protein intake of omnivore-based athletes with vegetarian athletes. The scientists observed that omnivore-based athletes could meet their recommended daily intake. In contrast, vegetarian-based athletes tended to slightly under-consume their daily protein intake goals by 10-20 g a day.[13]
Some strategies that plant-based athletes can follow include eating more significant amounts of protein per meal (and daily), incorporating different plant-based proteins into their diet to form complete proteins, and supplementing a plant-based protein powder.
Protein and Muscle-Building Tips
-Aim for a daily protein intake range of 1.2-2.0 g/kg body weight
-Eat high-quality protein sources at meals about every 3 hours
-Aim for a protein serving of 0.25-0.55 g/kg body weight at each meal
-If you’re vegan, vegetarian, or prefer to mainly eat plant-based proteins, be sure to eat a wide variety of plant-based protein sources. While most plant-based proteins are incomplete proteins, meaning they either lack (or have very low content) specific amino acids, they can be combined to form a complete protein. When you eat a variety of protein sources, you increase the likelihood of supplying your body with all the amino acids it needs to build muscle.
References
[2] Dietary protein intake and human health - Food & Function (RSC Publishing)
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6723444/
[5] Nutrition and muscle protein synthesis: a descriptive review - PMC (nih.gov)
[6] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6566799/
[10] https://pubmed.ncbi.nlm.nih.gov/27465374/
[11] The role of protein in weight loss and maintenance - PubMed (nih.gov)
