Popcorn is a whole grain food that’s high in fibre and relatively low in calories – all characteristics of a fat-loss-friendly food. In fact, when study participants were asked to describe feelings of satiety, they found that 15 calories from popcorn were as filling as 150 calories from potato crisps. 1 Those eating popcorn also went on to eat less at the next meal. Note: the stuff you get in the cinema, laden with butter and sugar, is unlikely to have the same benefits.