Simply: how much protein do you generally find to be ideal? Clearly you can't get away with much less than 20% or calories by protein or much more than 30%, but how much is best, for example, for satiation? Naturally it varies depending on activity and there's no need to keep track of the specifics (as though a hunter-gatherer would!) but what seems to be best as a trend?
A general baseline is that the body can't really utilize much more than 1g per pound of body weight. As well, this is probably on the high end of protein intake corresponding to somebody trying to gain lean body mass and muscle. I would think anywhere from 0.5g to 1g per pound body weight would be a good range to experiment with. I would let muscle growth or lean body mass levels be a good indication of the appropriateness of the intake amounts.
As far satiety, I would think that plenty of good fats will close up your appetite pretty well. So dial in the protein amount to appropriate mass gain and then substitute the rest with mostly fat for energy.
The amount of protein is going to have to span a decent size spectrum to accommodate specific body types and exercise profiles.
My personal take on this is that I'm torn between two competing lines of reasoning:
On the one hand there's the Jan Kwasniewski line, broadly defended by Peter over at hyperlipid that argues that you should only have sufficient protein and most of the rest of calories from fat; one reason being that more protein means more insulin and less insulin means more fat released from storage and so more satiation.
On the other hand almost everybody else in the paleo/LC world seems to think that more protein reduces hunger (indeed some people argue that protein is uniquely sating, whether the rest of calories is fat or paleo-carb is arbitrary). This would make sense if the effect of protein on glucagon, increasing gluconeogenesis would make less hungry than eating fat alone.
I'm wondering if the effects protein has on glucagon/insulin vary from person to person. For myself, the JK formula would mean no more than about 80g protein and the gram-per-pound formula would mean about 130g per day, which I tend to be in the middle of most days, leaning towards the protein heavy side.
This is something I'm still trying to sort out myself.
I know that when I use the Kwasniewski ratios I'm hungry constantly, I binge on fat (usually cream) and wind up gaining weight.
If I eat my body weight (in pounds) in grams, it's too much and I gain weight.
I seem to do OK with the numbers from the Protein Power Lifeplan, which puts me about .7g per pound of body weight. I'm still trying to sort out what carbs I should be eating for weight maintenance, so I'm not 100% sure yet about my macronutrient ratios.
Too much fiber (from green veggies in my case) is causing gas, bloating and poor digestion, so I'm experiencing big weight swings from water gain and loss, and this is why I'm not sure about any of my ratios yet.
Another one here using Dr. Kwasniewski's calculation for protein, .8g/Kg/Ideal Weight, per his formula for Ideal Weight. It works well for me.
I've read a number of posts at low-carb forums from folks eating this amount of protein.