Less work doesn't necessarily mean less willpower. Maybe you don't get very hungry, but some people do and for them that's what makes it take more willpower to fast than not fast.
Another thing to consider is that many people who don't feel like spending the effort to make breakfast will just buy something and eat it. Doesn't take much effort or willpower to stop at Dunkin Donuts or Starbucks on the way to work.
First there's the adaptation period. Even after you're adjusted you'll experience hunger sometimes, but once you start moving and have a coffee, tea or water, the hunger subsides. The only will power you'd need is just to have your morning drink before acknowledging you're hungry.
1. Wake up
2. Make Breakfast
3. Go on with day
vs
1. Wake up
2. Go on with day.