Air-popped popcorn is 387 kcal per 100 g. One of the lowest-density snacks by volume — bulk plus fiber makes it practical for a deficit, but oil or butter toppings can double the calories fast. Weigh plain, log fat separately.
How should I track Popcorn, air-popped?
Popcorn, air-popped is high in fiber. When it comes to Popcorn, air-popped, weighing beats counting every time. Snack pieces vary in size, and a handful from a bag can easily be 50–100% more than the label serving. Research (Almiron-Roig et al., Appetite 2013) shows that people consistently underestimate portions of calorie-dense snacks. Another common trap: multi-serving packages. The label might show 150 calories "per serving," but if the bag contains three servings, you are really looking at 450 calories. Always check whether values are per piece, per serving, or per package.