Would You Eat Less Chocolate If It Came in Smaller Pieces?

Two bowls hold the same weight of the same chocolate. One contains smaller pieces, so there are more of them to choose from. Would you expect the size of each piece to make any difference to how much you actually eat?

A classroom taste test approached that question with small and large commercial Mars bars. Dutch university students received either 15 small bars totaling 150 g or three large bars totaling 153 g. Each offer provided almost the same total weight, with a different number and size of individual bars. Participants could eat as much or as little as they wanted.¹

The chocolate was presented with its original wrappers either on or off, creating four combinations of size and wrapping. Participants had the opportunity to snack while completing an advertising task lasting about ten minutes and a taste questionnaire. The analysis included 162 students. After the snack, the researchers counted the intact bars and weighed leftover pieces. This let them calculate how many grams each participant had eaten, including parts of larger bars. The measure did not depend on counting pieces taken or asking people to remember how much they ate.¹

Smaller bars were associated with lower average consumption during that eating occasion. The difference depended on wrapping and was greatest when the bars were unwrapped: the small-bar group ate an average of 34.2 g, compared with 55.0 g in the large-bar group. Nearly equal amounts available had therefore accompanied different amounts eaten. The contrast did not require anyone to unwrap each piece, although the study did not establish why consumption differed.¹

These were manufactured Mars formats, not pieces cut from the same chocolate, and identical formulation was not established. The finding supports a possible effect of chocolate format under nearly equal availability, while leaving the precise two-bowl comparison unresolved. It describes a group average from one brief occasion, without predicting an individual's intake or establishing effects on later eating or body weight.¹

When you're describing chocolate, “a bowlful” and “a few pieces” sound clear enough. They still leave out the size of each piece. That's part of the snack you're being offered, alongside how much is in the bowl. So when you say “one more,” it's worth being clear about what counts as one.