Day 26 (Core) and counting calories

Today was Core Synergistics...only my second time doing it.  I found it a little easier this time, probably because I knew what to expect and I've been going over the routine to understand it better.  I tried it with a HR monitor on and learned that it burned 820 calories.

I was able to make it through the entire first section which includes 8 exercises without stopping.  I started to lose strength and endurance during the second section...particularly the prison cell push-ups (which I did maybe 8-10 of), the plank to chaturanga run (which I just did the plank and had to stop twice) and the walking pushups (once again had to stop twice).  There are just too many push-up-like exercises squeezed in too closely...my arms just couldn't hold me up anymore.

I actually completed the last section fairly well with the exception of the plank to chaturanga isos...I did the plank/chaturanga/plank and half a chaturanga before I could do no more.  Once again...a push-up like exercise.

Despite the difficultly (or perhaps because of it), I am really liking this workout.  I like that it is unique and focuses on the core.  Because of this, I think I may swap out Kenpo every week for Core.  Kenpo really isn't that challenging...all that I'll lose by dumping it is some balance work with the kicks.  However, I will get plenty of balance with Yoga and I think the Core will really add to what I am doing.

I'd been playing around with tracking calories and with encouragement from Stephanie Osborne (the Beachbody coach I purchased the P90X program through), I started today.  I used MyFitnessPal.com (the mobile app) and I was very surprised at what I saw.

I would normally consider today a day where I ate way too much and really fell off the wagon with Coke.  If I didn't look, I would assume today would be a day that the scale would start moving up.  Here's the overview:

Breakfast
-Protein Bar, 90 calorie Coke
Snack
-Peanut mix, half of a 240 calorie Coke
Lunch
-Panera half Turkey Bravo, large bowl of potato soup, baguette, small Coke
Snack
-Peanut mix, Protein Bar
Dinner
-five large stuffed pasta shells, salad, 90 calorie Coke
Snack
-Popcorn, Juice

That comes up to 2931 calories.  Subtract 820 and I netted 2111.  I've played around with dieting before and found I need 2200-2300 just to maintain weight.  The breakdown was 53% carbs, 31% fat and 16% protein (MFP tells me the targets should be 55%,31%,15%).  Since today was a huge Coke day (4 drinks), it now isn't surprising that I've lost 5-6 pounds in the three weeks when I had one Coke and less snacks.

I'll keep using MFP to track things for a while.  What I'd like to do is stay at NET (after exercise) maintenance calories (~2200-2300/day), stop the Cokes and replace those calories with protein rich foods/snacks.  Any ideas other than protein bars and peanuts?