I receive great questions everyday regarding nutrition. After I recently discussed a breakfast I ate that had 45g of protein the following conversation took place….
Q: I was under the understanding that your body could only absorb approx. 20gr of protein at a time so shouldn't you keep you meals snacks around that?
Protein absorption - "how quickly can our digestive system absorb amino acids into our bloodstream to use for our physiological processes?" Now - this is a hugely complex question because it is very hard to measure, and it is different person to person based on size, gender, muscle mass, type of protein ingested etc.
Food does not move through the digestive tract in the same order it arrived in. Protein in the stomach will stimulate a certain hormone that will delay "gastric emptying" (this is why you feel more full when you eat protein). As it delays the emptying of the stomach, it is in essence "buying you more time" to absorb the amino acids from the protein you eat. So you could eat a sub sandwich, and the carbs could move fully through your small intestine, but the protein could remain for a while longer.
Once the amino acids have been absorbed into your blood, the body then uses them for tissue growth, repair.... if there is leftover protein then it can be converted into glucose through a process known as gluconeogenesis.
Now, 20g of protein post-workout was found in this study to be the max amount needed to stimulate protein synthesis (in young men), which meant that eating more than 20g after working out did nothing more in terms of stimulating muscle growth. But there is a key difference here - anabolic response and protein absorption in one sitting are different things.
Back to my point about converting protein to glucose.... anything that you eat over the amount of the daily needs for your body will be stored and turned to body fat. One of the key things to note is that if you are following the proper macros for your goals (let's say weight loss) is that you body will 'burn that food' because you are in a caloric deficit.
This is not to say that nutrient timing is not important - it's just that your overall caloric and macronutrient intake should be addressed first.
Hope that helps. Coach Simon is our go-to guy when it comes to nutrition if you want to learn more!
- Dr. Alli