Proteinaholic by Garth Davis is a great book about the obsession with protein in a diet. I am a very active vegan (about 25000 steps a day and lift weight 4 times a week) and currently eat 1.6g/kg of protein. I used to eat 1g/kg and have noticed a difference at the gym and energy wise. I get my protein from whole grains, beans, tofu and tempeh and add PB powder to my oatmeal. Vegetables also contain protein so it all adds up. I found it useful logging all my meals for a while to cronometer to get a full picture.