There are guys who analyze their diets by percentage of each macronutrient.
I do it differently.
I take your lean bodymass and use that to calculate your daily maintenance Kcals. Then I use LBM to calculate how much protein you should be eating, then I add in 100g of fats and the rest is carbs.
13 Stone 9 Lbs works out to 191 lbs. 191 x 85% = 162 LBM
I have a formula I made up from some other formulas to calculate daily maintenance Kcals. Here it is:
BMR = 500 + (10 x LBM)
Your BMR = 500 + (10 x 162) = 2120Kcals
To get your body's actual caloric expenditure (maintenance Kcals), multiply by a factor between 1.2 to 1.9, depending on how active you are. 1.2 = sedate; 1.5 = moderately active. 1.9 = works hard all day long (i.e. hard physical work).
If you work out 3 to 4 days per week, but have a sedate job, we'll use 1.3 as the multiplying factor. If you have an active job and/or lifestyle, we might want to use a higher number such as 1.5. If you are running marathons or doing very hard physical labor all day, we might go toward 1.8 or 1.9.
2120 x 1.3= 2,756Kcals to maintain your current bodyweight.
You won't know if this is accurate until you eat that much food (weigh and log it in a journal) for a couple of weeks and see whether you gain or lose weight.
Of that 2700 Kcals per day I recommend for bulking or maintaining that you eat at least 250g protein per day, which is 1,000 Kcals, and no more than 100g fats per day, which is 900Kcals. The remaining 800Kcals should come from 200g carbs per day.
For more information, I have a thread on this.
http://www.theironden.com/forum/threads/16680-To-Be-A-Bodybuilder-Eat-Like-A-Bodybuilder