It still costs pennies on the dollar to make stuff like soda, so this wouldn't entirely solve the issue.  An awful lot of junk food has a pretty big profit margin precisely because it is junk.  It's just a bunch of stuff with no nutritional value loaded up with cheap sugar, salt and fat to make it taste good.    And things like meat aren't really the culprit.  Have you ever tried eating 4000 calories of meat?  It's really, really hard.  That's why fatties who can't lose weight any other way will lose weight on keto; if they stick to it then even they have a hard time eating enough calories.  I know that some still manage to do it (fatties gonna fat) but it's much harder.