Does treating ADHD as an adult sometimes change someone's relationship with food even without a specific weight-loss medication involved?

Commonly reported, yes. Many adults describe changes in their relationship with food after starting ADHD treatment specifically because of the broader improvements in impulse control, emotional regulation, and ability to plan and follow through on eating routines, independent of any direct appetite-suppression effect. It's frequently mentioned as an unexpected but meaningful side benefit of ADHD treatment rather than something the treatment was specifically aimed at. References: https://obesitycanada.ca/healthcare-professionals/adult-clinical-practice-guideline/

Wasn't even thinking about my eating when I started treatment for focus, but it changed a ton without me trying. Random side benefit nobody warned me about.