There's no one set ratio.. the "experts" debate the % on each...and take issue with the USDA recommendations
-- and there is no discussion on this in the SB book..
Each one of us is different, and may have health issues that impact on the % (e.g. folks with Kidney problems need to watch their protein intake.)...so with that being said.....
Here is a link to a site that provides not only recommended daily calorie intake, but the breakdown for you based on your age, gender, and lifestyle. It may hel you set a benchmark for each food type and will enable you to tweak it based on how your body responds to/processes each type.