It's mostly been a matter of substituting things I really like to eat that have fewer calories and fat for the other things I really like to eat that have tons of calories and fat, and keeping track of how much I eat of everything. I mean, yeah, I love french fries, but I really will be just as happy with a baked potato with a dab of sour cream and butter. Not to mention that on Weight Watchers I can have the fries every now and then, because WW treats me like a grown-up and gives me extra points to use for occasional treats and snacks.
In other news, we have, at last, released Tom into the house. It seems like forever, but I think the slow introduction with letting Tom live in the spare room a couple of days to let his scent in and then letting them "visit" through a cracked door has paid off. There have been isolated incidents of hissing and growling, but it's kind of hard to take it seriously when both cats are sprawled a couple of feet apart looking so relaxed it's hard to tell which one's making the noise.
Greebo has been doing most of the growling, but so far they seem to be fighting for who's going to be the submissive cat, since mostly they hiss, growl and then run away. There was one point when Greebo was working up a really intimidating growl and then had to stop to cough up a hairball. Not his most dignified moment.
In short, they're getting along as well as could possibly be expected at this point. I'm sure that there will be actual contact fighting at some point, but two days in it hasn't happened. They might not end up as buddy-buddy as Greebo and Sylvester were (see below), but that's okay, too.