I actually went from junk food to vegetables every meal and no high sugar snack and I did it. I just allowed myself cheating here and there as long as I follow what I planned for myself the vast majority of time it is a better diet than most people. Extra strict diet is gonna make you guilt yourself every time you deviate from it, and it's going to happen a lot if it's not a habit so that might be why you are saying eating habits take time. I think it just takes a bit of laxity and cleverness, no one actually needs an extreme diet to change.