Anyone who’s walked into a grocery store being hungry will tell that’s a very bad idea. Apparently, that’s not all. Making all sorts of important decisions on an empty stomach tends to make people settle for a small reward that arrives sooner than going the extra mile to reach a big reward at a later date, a new study found.

“We found there was a large effect, people’s preferences shifted dramatically from the long to short term when hungry,” said Dr. Benjamin Vincent, a psychologist at the University of Dundee in the United Kingdom. “This is an aspect of human behavior which could potentially be exploited by marketers so people need to know their preferences may change when hungry. “

Vincent and colleagues asked 50 participants questions relating to food, money, and other reward-based topics twice: when they were full and when they skipped a meal.

Quite unsurprisingly, hungry participants were more likely to settle for food incentives that arrived sooner. However, the researchers found that this tendency to settle for immediate but less satisfying rewards crossed over to other aspects of life, which were totally unrelated to food.

“People generally know that when they are hungry they shouldn’t really go food shopping because they are more likely to make choices that are either unhealthy or indulgent. Our research suggests this could have an impact on other kinds of decisions as well. Say you were going to speak with a pension or mortgage advisor – doing so while hungry might make you care a bit more about immediate gratification at the expense of a potentially more rosy future,” Vincent said in a statement.

When offered the choice between three different types of rewards, hungry participants generally preferred smaller hypothetical rewards that were awarded immediately rather than larger ones that would arrive later. When the participants had lunch, they were typically willing to wait 35 days to double the reward, but when hungry they grew too impatient being willing to wait only 3 days.

“This work fits into a larger effort in psychology and behavioral economics to map the factors that influence our decision making. This potentially empowers people as they may foresee and mitigate the effects of hunger, for example, that might bias their decision making away from their long term goals,” he added.

The findings, which were published in the journal Psychonomic Bulletin & Review, seem to concur those of a much more famous experiment, the so-called “marshmallow test” performed by Stanford psychologists in the 1960s. Put a marshmallow in front of a child, tell her that she can have a second one if she can go 15 minutes without eating the first one, and then leave the room. Whether she’s patient enough to double her payout is supposedly indicative of a willpower that will pay dividends down the line, at school and eventually at work.

The new study shows that hungry people will make more impulsive decisions even when their outcomes will do nothing to relieve hunger.

“You would predict that hunger would impact people’s preferences relating to food, but it is not yet clear why people get more present-focused for completely unrelated rewards,” Vincent.

“We hear of children going to school without having had breakfast, many people are on calorie restriction diets, and lots of people fast for religious reasons. Hunger is so common that it is important to understand the non-obvious ways in which our preferences and decisions may be affected by it.”