In Hebrew, Pesach or Pasach means to skip over. This was the indication that Hashem will skip over the homes that were marked during the plague of the first born sons (or makat bechorim).
When thinking about health and nutrition during any holiday, we like to say “the calories don’t count”, as if to say the calories will “skip over us”.
But let’s be realistic here; no matter how special the day, whatever we eat will still count as it always has and always will. The calories won’t “skip over” us just because it’s a holiday. Remember to look at nutrition facts and enjoy the chag while still keeping to your plan.