Beverly Fay is right. One can totally overestimate the amount of calories needed during and after long or short runs. I won't even smell Gatorade now after overdosing during marathon training two years ago.
It is easy to make excuses to eat overly well post running - and dive right into desserts and french fries and other bad choices like a whole bag of potato chips. This is the time to eat the right carbs in moderation. Pasta is good, but 2lbs of pasta is not good.
It is possible to lose a few pounds (but not 15) in your training. By running within your fat burning zone with use of your heart rate monitor, you will burn more, and save your knees in the process. You should take your long runs at a civil pace and save interval runs at higher tempos for midweek. Gets the heart rate in that upper zone.
This is the time not to cut your calories but to make more sensible choices about them.
Sounds so easy too - since every body and metabolism is different, you will have to find the right mechanism to burn fuel like a rocket. Good luck - see you in October!