When people cannot see their food, they tend to think they drank more if the liquid is poured into many small containers rather than fewer large ones. This overestimation occurs because visual cues...

We’ve reviewed one assertion on this topic, and it suggests that when people can’t see what they’re drinking, they tend to believe they’ve consumed more if the liquid is poured into many small containers rather than fewer large ones. This appears to be tied to the absence of visual cues, which people often rely on to estimate how much they’ve taken in — even though those cues don’t change the actual amount consumed [1]. What we’ve found so far is limited to this single assertion, which is supported without any contradictory evidence in our current review. The idea is that without sight, people lose a key reference point for judging volume, and the number of containers may create a misleading impression of quantity — like thinking five small glasses add up to more than one big one, even if they hold the same total. This doesn’t mean people drink more or less; it means their perception of how much they drank shifts based on how the drink is presented. We don’t know if this effect holds across different populations, settings, or types of liquids. We also don’t know how strong the effect is or whether it changes with experience, hunger, or awareness. The evidence we’ve reviewed so far doesn’t explain why this happens, only that it appears to occur. For everyday life, this suggests that if you’re trying to track how much you drink — especially without looking — the shape and number of containers might trick your brain into thinking you’ve had more than you actually have. Paying attention to the total volume, not just the number of cups, could help avoid that mismatch.