Make oil-free microwave popcorn by buying a collapsible silicone bowl, filling it with kernels, and nuking it for 3 minutes. Low calorie snack, no mess, no cleanup. I find salt sticks to it best afterward by sprinkling with a little water.
Source: I started getting fat of popcorn every day and am typically considered skinny/fit. Then I read the label and got sad.
The comment you reply to specifically mentions oil-less popcorn which is a low calorie stack and a good source of fiber once you get used to not lathering it in butter or olive oil.