Does coffee instead of breakfast affect cortisol?

Coffee can make some people feel alert, shaky, anxious, or more acid-prone, especially on an empty stomach. Skipping breakfast is not automatically harmful for everyone, but combining no food, caffeine, poor sleep, and stress can make the morning feel rough. Cortisol naturally rises in the morning, so the goal is not to fear cortisol; it is to notice whether the routine works for your body. If coffee instead of breakfast causes jitters, reflux, headaches, or energy crashes, try eating something simple first or reducing caffeine and compare the difference.Mmedlineplus.gov