I’m not so sure both would be nurture. I also don’t believe the premise has anything to do with something as mundane as habits.

You could be a hardcore $political party member, but nothing about that is nature. That’s entirely a result of your environment.

As far as I understand, nature vs nurture is more designed to explain/blame academic performance, ability to manage money, pressure, etc. I remember hearing an old friend explaining it as “a way for the rich to justify why poor people shouldn’t be making financial decisions“.