Should you eat protein from animals or vegetables? Proteins are made up of amino acids, there are 20 different amino acids in found in protein, 9 of which are essential (the body cannot make them therefore they must be ingested). Protein from animal products is generally called complete protein, as it contains all the essential amino acids, foods such as meat, poultry, fish, eggs and dairy products. Incomplete proteins have low amounts of some of the essential amino acids, and therefore it is important to combine different incomplete protein sources in a vegetarian and vegan diet to get the full amino acid profile. Good sources of protein for vegetarians are legumes (peas, beans, peanuts, alfalfa), seeds and nuts.
The amount of protein you require will depend on your activity levels, gender, age and health. The Recommended Daily Intake for sedentary adults (in Australia and NZ) is only about 0.8 g/kg BW (1). If you review the ACSM nutrition and athlete performance guidelines from 2016, it is recommended for active people that 1.2 – 2.0 g/kg BW/d and higher amounts maybe required for shorter periods of time during intensified training, or when reduced total energy intake (2). It is recommended that after training, the amounts of protein to consume are between 20 – 40 g whole protein, however amounts greater than 40 g will not improve MPS (Muscle protein synthesis) any further (3).
It is recommended that protein intake is spread over the day in small feedings, or about 0.3 g/kg BW at each meal or snack and after resistance training. This is thought to improve MPS. So for a 70 kg male that’s about 21 g protein at each meal or snack (maybe 6 in total throughout the day), which is equal to about 126 g daily = 1.8 g/kg BW daily – perfect for a strength trained athlete (4).
Most people who train in the gym, particularly strength-trained athletes, consume protein shakes. They are marketed everywhere for everyone, and many people consume these on a daily basis. There can be good justification for consuming these products after training, such as an athlete finds it difficult to eat after training (i.e. nausea), or they have no time to eat, or they can’t eat enough protein, or they want the product for convenience. All valid reasons to consider using these products. Just remember that to increase strength and lean body mass, just consuming a protein shake will not do this, but if you include a tough training session then the protein after training will be effective whether it’s from food or a shake.
Leucine, Isoleucine, Valine are the 3 essential amino acids and are often referred to as BCAAs (branched chain amino acids). These can usually be obtained in a 25 – 30 g serve of protein without necessarily having additional BCAAs. There are also glutamine and arginine taken for recovery purposes with or without protein shakes. These may assist in recovering faster, but again, they are found in adequate amounts in a high quality 25 – 30 g serve of protein. If you can’t eat this protein from food after training, then again shakes may be a useful addition to your diet.
If you want to discuss your specific protein requirements and what you should take when, then consult an experienced accredited or advanced Sports Dietitian to determine how much, when and what proteins are best for you. Dr. Gary Slater provides a fantastic presentation for Megabite on Protein Needs, and covers in depth the research and evidence behind supplements.
2. Thomas, D. T., Erdman, K. A., & Burke, L. M. (2016). American College of Sports Medicine Joint Position Statement. Nutrition and Athletic Performance. Medicine and science in sports and exercise, 48(3), 543-568.
3. Kim, I. Y., Schutzler, S., Schrader, A., Spencer, H. J., Azhar, G., Ferrando, A. A., & Wolfe, R. R. (2016). The anabolic response to a meal containing different amounts of protein is not limited by the maximal stimulation of protein synthesis in healthy young adults. American Journal of Physiology-Endocrinology and Metabolism, 310(1), E73-E80.
4. Areta, J. L., Burke, L. M., Ross, M. L., Camera, D. M., West, D. W., Broad, E. M., ... & Hawley, J. A. (2013). Timing and distribution of protein ingestion during prolonged recovery from resistance exercise alters myofibrillar protein synthesis. The Journal of physiology, 591(9), 2319-2331.