I think us guys who have been in this life for many years assume that the starters already know this information.. but obviously not.
The higher the fat content of a food(animal) product - the slow the digestion rate of the protein. Only animal/Fish/whey/casin counts towards your daily intake of protein.. not beans/pastas/rice/legumes.. blah blah... basicly - if it was either walking/running or swimming at one point - it counts
You need to learn and read! there are pages of information out there... but always listen to your body and go off how you feel.