Quiz : How Much Do You Know About Proteins?

Protein plays several crucial roles in the human body, most notably in the production of enzymes, peptide hormones, neurotransmitters, RNA transcription from DNA, and muscular growth. Unlike glucose, the human body cannot produce protein, so it must be ingested. However, it does not necessarily mean that meat or whey must be consumed as both vegan and vegetarian diets are both sustainable, but they still contain some indirect protein sources. If one were to try and purposely consume little to no protein (e.g., fruitarian), they would likely pull amino acids from pre-existing muscle tissue to fulfill bodily functions. In the long run, this would not be conducive to muscular hypertrophy and an increase in the cross-sectional area. Still, it is certainly possible to survive without consuming any protein-rich foods. On top of that, fruitarians must consume copious amounts of fruit to sustain caloric needs. Thus they will likely be ingesting a variety of incomplete amino acids, which could fill some of the nutrient "gaps" presented by a lack of animal products.

Depending upon the timing of your pre-workout meal, you may still have amino acids circulating in your bloodstream, so it would be unnecessary to try to re-stimulate muscle protein synthesis due to its refractory nature. Essentially, the most straightforward analogy is a gas tank - if your gas tank is 75% full, do you need to put in another whole tank of gas? No, it will just overflow. Realistically, a 3-5 hour digestion window from your last meal would also include your workout. So, if you ate at 3 pm and worked out from 4 to 5, then you would have another hour or two before it became necessary to ingest a meal. Now, can you eat sooner than this? Sure, but given the current research, it would seem that this is not physiologically necessary.

Excess protein has a tough time being converted to dietary fat because the only amino acids with the carbon backbone structure that can be converted to adipocytes are leucine and lysine. Not only that, gluconeogenesis (converting amino acids into glucose) would need to occur before they are stored as adipocytes, and this process is very rare in humans. Interestingly, emerging research shows that excessive protein intake doesn't augment body weight, although issues were in a caloric surplus.

Protein has the highest TEF (thermic effect of food), meaning that it is metabolically costly to process and requires 20-35% of its energy to be digested and assimilated.

Protein will not cause kidney issues, brittle bones, nerve demyelination, or hair loss for healthy individuals. All of these are myths, provided the person has preexisting conditions which would affect the digestion or assimilation of protein within their body.

Current research has shown that 20-30 grams maximally stimulate muscle protein synthesis. However, this number will change for each individual, depending on their meal frequency, macronutrient intake, personal preference, and performance factors. For example, if you only eat three times a day as a 150lb male, then you'll need 50 grams at each meal which is higher than the recommendation above. But, to quote Alan Aragon on the subject: "Those who choose to meet their protein needs with three meals will assimilate it just as effectively as those who get their allotment over six meals. Digestion/absorption is an efficient process whose duration varies according to the dose size (our digestive system is way smarter than we give it credit for). Therefore, individual preference and tolerance should ultimately dictate protein dosing per meal."

These foods contain roughly 24-26 grams of high-quality protein.

Most research suggests that maximal muscle protein synthesis occurs around 0.8-1g/lb of bodyweight. However, a growing body of evidence indicates that protein needs might be slightly higher when a caloric deficit is maintained in the long term.

Current research would suggest that there isn't a limit to how much protein you can digest in one sitting. It won't all be efficiently utilized for muscle protein synthesis at once, but that's not to say that if you ingest 100g, your body won't process it. Once muscle protein synthesis is maximized, nitrogen is stripped from protein before it eventually ends as urea in your urine, and the carbon skeletons are metabolized.

While whey protein from concentrate has a BV of 104, isolate is higher at 120+ in some instances.