Today we answer the question; what exactly happens when we eat too much protein?
TLTR; you pee some out and convert some to glucose.
Fancy a science lesson? Read on > before we jump into this, here are five notes on high protein diets;
1) High protein diets are superior for fat loss when calories are restricted.
2) Once you have adequate amount of protein in the diet to support muscle growth, more doesn’t equate to greater gains.
3) You can digest and absorb more than 40g of protein in one meal.
4) Muscle protein synthesis (muscle growth) is maxed out at ~0.4g/kg/bw (32g for an 80kg guy).
5) High protein diets are not harmful to health unless you have pre-existing kidney issues.
BTW, this is going to be a full on nerdy D2EW!
So; everything that’s made of protein in the body is constantly being broken down and rebuilt in a cyclical nature. This essentially how muscle growth occurs, but only when synthesis exceeds breakdown. This is exactly what happens when we have a lot of muscle damage; protein turnover (growth + breakdown) is very high.
Here’s the very interesting thing; an average adult makes about 350g of protein per day (muscle, skin, hair, nails etc) – but, this is double the recommended about of ~2g/kg for an 88kg male. So, why do we only need to consume half?
Now, we know that protein acts as both the signal and building blocks for new muscle. The protein/amino acids for the building blocks are obtained in three ways;
1) From our food.
2) From broken down muscle that’s been recycled.
3) From recycled urea in our gut.
Once these amino acids are freely available for the body to use, they are directed to replenish and ‘feed’ the amino acid pools within your cells. These amino acid pools then serve the tissue for growth and repair.
This is why we don’t need to eat upwards of 300g of protein per day as all you’re doing is topping up the amino acid pool.
Since the amino acid pool lies within a tight range, we can’t store more protein (unlike fat) unless you potentially have bigger muscles.
Therefore it gets converted.
When protein is in excess, 3 things happen;
1) It’s converted into urea and excreted via urine.
2) It’s converted into glucose via a process called gluconeogenesis.
3) It’s oxidised and makes ammonia, then excreted via urine.
So, you pee some of it out and you convert some of it to glucose. This conversion into glucose then manages blood glucose and aids glycogen replenishment.
Make sense folks? Class dismissed.