You may see an increase in moodiness or agitation when a stimulant is wearing off. Some advise to try to eat a good amount of protein before that time so try to help. If it continues every day, you probably need to discuss it with your doctor.
It’s true that ADHD medication dampens the appetite in most people, but not all. I wouldn’t jump to the conclusion that you need a higher dose if you don’t lose your appetite.
Here’s a great guide on ADHD medication:
ADDitude Community Moderator, Author & Mentor on Parenting ADHD, Mom to teen w/ ADHD, LDs, and autism