Actually, most of the protein you consume passes through the intestinal lumen at which point it is then considered “absorbed.” Every tissue needs protein and what isn’t used for protein turnover is deaminated and turned into glucose or other intermediaries.
The issue is actually what can be directly converted into muscle cells and the rate limiting factor here is muscle cell ribosomes can only translate so many new protein molecules in a given time and IN THE BEST OF CIRCUMSTANCES this is limited to about 10g of protein taken up by muscle per day.
While eating high doses of protein is indeed critical for maximizing this response, above a certain point, more doesn’t lead to an increase of muscle protein synthesis. Any additional amount of protein ingested isn’t going to harm you, but those calories could be spent in better ways. Not to mention it’s expensive and a chore to prep and eat.
The advice you may have heard for a daily protein intake of 1 gram per pound of total body weight is a fine starting point. However, this number wouldn’t work for someone with high body fat and using lean body mass would more appropriate. ~2.2-3g of protein per kg of LBM is where you want to be.
But body fat measurements are notoriously inaccurate?? Well, measuring body fat doesn’t need to be perfectly accurate to get your protein target. A simple waist and neck measurement (and hip for women) punched into the Navy body calculator works fine for this purpose.
Protein requirements change when actively losing weight, and as you age. You need more protein in a deficit than if you are in maintenance or massing. And as you age you become less protein sensitive, meaning you need more of it to get similar responses than a younger person. So, add 10% to your daily protein requirement for each decade of age over for 40.
Eating animal source protein spaced out between three to four meals per day and eating about 2.2g of protein per kilogram of body weight per day is going to be a good starting place for most people. Just consider your age, your diet phase, and what sources pf protein you are eating. If you are less than optimal in those criteria then you will need a bit more protein per day.