Is pizza really that bad for you though? I had pizza for my tea last night and it was delish, however I do make my own, including dough and don't smother it with cheese (I may just be deluding myself though but I'm quite happy in that delusion). I'd faint if I had the level of food you've listed in a day and that's without exercise - I eat constantly. I'm quite similar to Trio in that I tend to stay quite stable, I'd happily lose half a stone but wouldn't want to be lose more than that and if I try to cut food down I can cope for a couple of days then my body demands food.
After a tough ride or run (particularly run these days) I'll have a recovery type drink as soon as possible after I finish which stops the hoover everything in sight munchies later. I also plan a menu out for an entire week so I know what I am having and can just get on with making it. I also find carb loading doesn't work for me, I can eat pasta, rice and potatoes each meal all week and I'll still run out of energy after about 2 hours if pushing, a bit more if not. My OH and a couple of the guys I ride with seem to be able to make it work for them but I can't. I don't consciously increase my food intake or change my diet prior to a big ride or run but I do have to pay more attention to my nutrition during the ride than the lads I ride with, if I don't fuel myself well enough during then it will take me a while to recover from it, recovery drink or no. On a ride over about 2.5 hours with the lads I'll use energy drink, they generally won't bother.
I have a 15 mile trail race over Garburn pass tomorrow (don't go riding round that area tomorrow!) and I haven't changed the what I eat at all but I have had a relatively light training week and I find that helps me more than anything else and I have actually eaten less this week than normal. I will have four energy gels (can't stand energy drink when running) with me to make sure I have enough fuel to get me round without bonking after about two hours whereas there will be other people who'll manage the race on nothing but water and a piece of toast for breakfast.
I will probably also find that I will be really hungry on Sunday, my body will be repairing itself after the run and will need fuel to do that. I used to try to vary food amounts depending on the amount of exercise I was doing in a day but I found it easier to average it out over a week and consume roughly the same amount of calories each day as I would often be hungry the day after long rides/runs, though that was when I was paying attention to my diet, I dont really these days, my diet is pretty good, my wine consumption on the other hand....
Have thought about restarting a food diary to make sure I'm eating enough, and see how much wine I'm drinking...