Just a few ideas to get you going:
'Well I've been soo good the last few days'
'censored man, I just went for a 10k walk, I think I can handle a triple cheeseburger' (this is mine lol)
'Well my non calorie counting day's Wednesday but maybe I should just change it to Sunday'
'IT'S MONDAY I'M BLOODY DEPRESSED GIMME SOME CHOCOLATE OR MY BOSS DIES!!!

*craves triple cheeseburger* ... *no pickle*