“I will” and “I will not” are powerful words.
They get rid of the gray areas, in-between, ambivalence, and maybes of situational decisions.
“If I go out to the ball game Wednesday, I might have some nachos and cheese” is basically saying “I have no idea what I’m going to do.”
“I’m not having refined food until Friday when I go out with friends” is clear.
You no longer worry about what you’re going to do on Wednesday. You may eat before you go, or bring an apple and some of your favorite nuts and jerky, but the decision has been made already and you’re no longer vulnerable to peer pressure or lack of preparation.
Rigidity is rarely your friend, but well-understood boundaries make decision making a lot easier.