At any given time, you have the potential to undergo beneficial changes in your thoughts, choices, and habits. You can make choices that move you in a positive direction, toward God and health or in a negative direction, away from God and toward poor health.
However, if you don’t actively discipline yourself to make wise choices, you might, by default, make foolish choices. If you don’t intentionally identify what is negative in your life and then reject it, you may, by default, continue to allow it. You have to take a pro-active, aggressive stance if you want to control your thoughts.
Passivity (lack of movement and decision) is not a wise approach. You’re either with God or you’re against God, according to Jesus. If you aren’t constantly on the defense, moving, watching, and guarding yourself against the prowling lion (the devil), you’re constantly on the verge of falling prey to the lion. “For God did not give us a spirit of timidity, but a spirit of power, of love and of self-discipline” (2 Tim 1:7).
In terms of weight control, you must actively guard your thoughts, not passively let your thoughts wander. Be on the defensive. For example, if anxiety drives you to eat, actively and aggressively (in your mind) grab the anxiety by the throat and say, “NO! I refuse to let you control me.” Then quote Scripture, e.g. Phil 4:6, “Do not be anxious about anything, but in everything, by prayer and petition, with thanksgiving, present your requests to God.”
“Finally, brothers and sisters, whatever is true, whatever is noble, whatever is right, whatever is pure, whatever is lovely, whatever is admirable—if anything is excellent or praiseworthy—think about such things” (Philippians 4:8 NIV).