Thanks, I am still personally learning about these issues, but this link goes into more depth as to why higher protein is a good choice..
In terms of fat vs. carbs - one relevant aspect is that fat has twice as much calories per gram as carbs, so you would need to eat significantly less to get the right carbs for you - which may or may not be an issue depending on each individual's needs. I am sure I will be able to give a more detailed response once I have learned more!