They're getting a hell of a lot more data from you than food preferences. They silently collect data even when you aren't using the app, and they take a TON of data: https://old.reddit.com/r/assholedesign/comments/1cjtywo/the_...

At least on android devices you don't even have the option to disable a ton of access to things like sensors.

That data they collect isn't just about ads either. They'll throw you a deal every once in a while to keep you handing over that data, but they're figuring out how much money you have, when you're most vulnerable to suggestion and least likely to resist, all so that they can adjust their prices just for you in order to make sure you're paying as much as possible.

Even with notifications turned off, everytime you open your phone and scroll past the M section on your phone they get free advertising. It may not seem like a big deal, but once you start seeing the gross incentives and manipulation so many of these companies do you begin to notice.

Plus what the other poster said with the massive data dump you're actually giving them.