I love running the numbers, too! I mostly do approx. how many calories I need to eat to lose X lbs, and I often have a flexible time goal, so that adjusts the calories, too. I even make charts and stuff to keep track (which I find really fun).
How did I get here? No favorite meal a week, just too much enjoyment of too much food.
But I have gained about 10 lbs a year pretty consistently since I was 13 at 130 lbs. And then I started losing weight at 21 and about 210 lbs.
So, that's 35000 calories more than I needed each year.
Which is about 675 too many calories a week.
And about 96 too many calories a day.
I used to love fruit snacks (still do!), and I'd eat at least one a day. They're about 100 calories each. If I hadn't eaten that, I might not have gained 10 lbs a year.
Or, I used to also love rich soups. I'd have at least two bowls a week most weeks. That's easily over 675 calories a week. If I hadn't done that, I may have even lost weight.
And like you said, OP, I know it doesn't exactly work this way, but it IS a lot of fun to run the numbers.