A quick Google search will tell you that your protein intake should be 0.8 g per kilogram of body mass, in general. This places the average sedentary man at about 56 grams per day and the average sedentary woman at 46 grams per day. That being said, if you’re going to the gym and working out properly, those estimates are not for you. Obviously you need more protein in order to build muscle, but the question is how much? The problem with that question is there are not enough studies in this particular area in that can give you give you definitive answer. Some studies even suggest that the 0.8 g per kilogram figure underestimates our needs. This means even the 56 grams per day recommended intake is not enough for the average man, let alone someone who is actively trying to build muscle.
There is no conclusive research as of yet that can tell you what the most efficient protein intake is. Depending on whom you ask, you will be given different information. Some supplement manufacturers would let you to believe that your needs are as high as 4 grams per pound, which is quite frankly overkill. A common myth is that if you consume too much protein it will destroy your kidneys, but at this moment there is no scientific data backing up that hypothesis. Even so, you probably don’t need that much protein on a daily basis unless you’re a professional athlete, and even then it’s still debatable.
The general rule of thumb based on most research and experience in the gym setting is that approximately 1 gram per pound of bodyweight is a good starting point. You should see good results with this protein intake. If you feel like your gains have started to diminish, then you can consider increasing the dose. After all, with time it’s possible that your needs have increased, either because you’ve started to work out more intensely, or because you’ve gain lean body mass and more protein to support it.
If you’re trying to lose weight but want to keep your muscles in the process, increasing your protein intake is a great way to do that. Keep in mind that if you’re overweight or have a high percent body fat, it’s a good idea to base your protein intake on your lean body mass.
Bottom line is that 1 to 1.5 g of protein per pound is where the magic happens. Start from there and then make your own adjustments. Some people prefer to take 2 g per pound hoping for better gains, but at the end of the day your body has limit of how much muscle it can synthesize. Also, it’s not just about protein, either. You can have 5 grams per pound per day of high quality animal protein and still not get the results you want if you don’t train hard enough. Getting your macronutrients is important, but so is proper training.