You would not believe how many times I've heard people claim that poor people are fat because they can only afford junk food. I've literally had to break down actual prices from my shopping receipts and give examples of meals to show these people that you can easily eat healthy food every day for around $100/month - or even less. And then they still don't believe me and want to argue about it.

Eating healthy isn't a financial problem - it's a psychological one. Most of the time, it just comes down to laziness. If you never try, of course you won't be able to change your habits or be healthier. It's not exactly the easiest thing in the world to pull off, but it's certainly doable with a little bit of willpower and effort.