What happens if you only eat canned foods for the rest of your life?

Your diet might be limited by availability, but you won't necessarily be any unhealthier depending on what you eat. 

You live, assuming you eat a healthy mix.

You're consuming far more salt and high fructose corn syrup than you should, so you can anticipate some health problems, especially when you're older.

if you eat the healthy one,s no problem.

Nothing, some good meals can be made from them.

Probably diabetes or high blood pressure, due to all the high fructose corn syrup and salt contained in canned foods.