> protein does fill you up faster

You are being pretty fast and loose with your language here so I will alight what I think you are trying to say.

"Fill you up" I must assume means that you are implying the state of feeling "full" or satiated.

There is really only one study in the field of broad food source satiety: https://pubmed.ncbi.nlm.nih.gov/7498104/

Potatoes are the most satiating food at 323% that of white bread.

The second is Ling fish which is a source of protein, but another one of my assumptions is that when you say 'protein' I am doubtful you mean 'ling fish'. So assuming you mean a 2026 American definition of 'protein' you're probably referring to cow flesh (beef) which is only 176% of white bread, almost half of potatoes.

So, in the future I would suggest spreading the word and correcting your comment by saying "I mean potatoes do fill you up faster"

> I mean protein does fill you up faster and better with fewer calories which is good for weight loss or management.

Thank you for exemplifying the problem so clearly - conflating protein with fat when we're really talking about a simple carbohydrates issue of high energy density with negative satiety.

Excess protein is excreted renally, it's easy to overdo and can cause serious problems.

Not than fat. Fat fills you up fastest, per calorie.