U.K. researchers have found that your hunger is a bit of a mercurial beast, as your short-term memory plays a hand in your perception of fullness (or lack thereof). According to Time, the way that you remember the portion size of your last meal can determine how hungry you feel for the next.

This is based on a study appearing in the journal PLOS ONE, in which the researchers presented 100 adult participants with two serving sizes of tomato soup (10 ounces versus 17 ounces). The participants were asked to finish their soup.

For half of the group, their bowls were rigged to refill or drain the contents imperceptibly. Those who ate more actual soup reported being fuller immediately after eating. But a few hours later, perception became the determining factor in how hungry participants felt—those who thought they had eaten 17 ounces indicated that they were less hungry, even if they had only had 10 ounces in reality. The lead author Jeffrey M. Brunstorm finds “the memory of our previous meal may have a bigger influence on our appetite than the actual size of the meal.”

All of this supports the importance of mindful eating, which means putting away your smartphone and turning off the TV. Focus on the plate or bowl of food in front of you so that you will have a truer sense of what you ate.

[via Time]