Yea that was a shocker for me too. Maybe that works if you are staying in your parent's house basement, but I just can't see anyone anyone in the US pay $650 for living expenses.
There are a lot of small towns in America where you can rent for $350 or $400 per month.
I lived on a $50 per month grocery budget when I was 21 (maybe $75 today). Worked a part-time job that paid for my apartment, and worked as an entrepreneur the rest of the time.
I think it's pretty amazing how low your bills can be when you're really young, have no family, and little to no concern about health issues (I had no health insurance for a decade, never had a single health issue either, which is purely luck / genetics).
after rent, having no car (bicycle) and no data plan cut things down even more.
only real issue is lack of medical insurance.
was 5 minutes walk to nearest grocery and 5 minutes bike to work. Though in the winter I would walk (half hour) because biking on ice is deadly.