First of all, thank you all for being here and being supportive. You all have been a great help as I still learn the ropes.

My question now is how much protein should I consume? I read Mark's guide that stated .5 g per lb of lean body weight, and up to 1 g for the active.

I have also read advocates of gauging protein on percentage of calorie intake, i.e., 15% of total calorie intake.

My problem is that I am drastically underweight and so am consuming an inordinate amount of calories for my body weight. If I eat protein according to Mark, I would require 39 g of protein at .5 or 77 at 1 g (yes, I am dangerously underweight). However, if I judge it by the percentage of caloric intake at 15% total, I should get 86 grams--a lot more than the 39 or 77.

I have heard that protein is the building block of the body, and I am trying to put on weight. But I have heard it is DANGEROUS to consume too much protein as well--it begins leaching from bones as too much is passed and I can't remember all.

In short, how much protein is good? Is it better to base on body weight or on caloric intake? How much is dangerous? What is healthy to put on weight?

Related, but not quite, is if I do reduce protein from 86 down to somewhere b/w 39 and 77, is it better to replace that with carbs or fat? (I get about 170 g. carbs right now, and the rest--about 50% of caloric intake--from fats).

Any advice would be appreciated.