I used to justify it with "I've had a shit day, I deserve to be able to have something for the convenience" - not to mention, I don't have a car so realistically it was "Do I want fast food or not".
Then I started to realize that every day tends to be a bad day for me, due to a multitude of reasons. I live paycheck to paycheck (which is why I don't have a car in the first place) and the amount I was spending on takeout was way too high.
Now the only time I do so is on Fridays because my workplace lets us spend $25 on their tab just for joining the weekly staff meeting. Aside from that, I might order a takeout once, maybe even twice, during a pay period as a "congrats for making it through last month" but I'd like to even stop doing that ideally.