Scenario: You want to maintain, and you are eating maintenance calories but maybe only getting 70 - 80 grams of protein. You still lift heavy ass shit. You shouldn't lose any muscle... right?
70-80 grams of protein / day? Depends on your weight, but most likely that is enough protein to maintain mass. Most magazines and bodybuilders would recommend much higher levels of protein, but that's a topic that's pretty highly debated I think. In general it's safer to be on the high side, but I would take a gamble and say that 70-80 grams per day will let you keep your muscle as long as it's spread throughout the day with a variety of good sources.
It depends solely on your bodytype, weight, and macro breakdown.
But unless youre a small female its not enough.
You need enough protein to replace the amount broken down during your workout and from general protein turnover within the body.
Since, it is pretty impossible to know how much that amounts to on a daily basis, I would think to aim for 1gm/lb (of LBM) and err on the side of excess, should prevent any muscle loss...just my 2 cents