One of the biggest overlooks when it comes to cooking dinners or any involved meal with multiple ingredients is accounting for the calories each ingredient will take. Let's say you're cooking pasta and you want to include the sauce, some seasonings, some things to mix with the pasta .etc
You're done but you won't know what each bowl of that finished pasta will be like per serving. That's why you have to take into account, all of the calories of the ingredients. That tablespoon of vegetable oil you use, that's 100 calories. The sauce you're gonna use, that's probably another 100. The pasta, 140 probably. It doesn't work as if the calories are going to vanish by the time you're finished cooking said meal. Each bowl you could have, could amount to over 500 at most, but you may not know it and it's easy to overlook.
That's why also, it looks like people pack on weight so easily when they're down to just dinner meals to eat. They pile up fast.
Glorious.