We’re always told never shop for food on an empty stomach, but is it true? NZ researchers found out

Sunday, 21 June 2026

University of Otago researchers found evidence that hunger makes people imagine food more vividly, supporting the advice to never shop on an empty stomach.

Participants consistently imagined food textures like potato chip crunch more vividly than tastes, surprising researchers in the cognitive psychology experiment.

Researchers hope the study will improve understanding of overeating, dieting and why some people are more susceptible to food cravings than others.

It’s a scenario I know all too well.

Walking into the supermarket hungry with the goal of buying a couple of vaguely healthy items, only to come out 20 minutes later, weighed down with dubious, calorie-laden goodies.

“Never shop on an empty stomach” is one of those pieces of advice that sounds like an old wives’ tale, yet somehow proves true time and time again.

Now researchers at the University of Otago – Ōtākou Whakaihu Waka have found there may be some science behind it.

The study explored how hunger influences our ability to imagine food and whether those mental images become more vivid depending on our metabolic state.

Associate Professor Mei Peng, of Otago’s Sensory Neuroscience and Nutrition Lab, was a co-author of the study.

“There’s lots of anecdotal evidence out there suggesting that when we're hungry, we crave things and have more vivid imaginings of food, but it hasn't been tested empirically very often, so that's what we did.”

More than 60 people took part in the experiment. Participants were asked to fast before imagining the smell, flavour and texture of different foods. They then repeated the exercise after eating a full meal.

“It’s very much a cognitive psychology experiment,” Peng says.

“We gave them food cues, such as pictures of food, and then asked them to imagine eating that food and rate how vividly they could imagine its texture and flavour.”

One finding that surprised the researchers was the importance of texture.

Participants were often able to vividly imagine not only the taste of foods such as chips, but also the crunch.

“Some people can imagine taste very vividly, but others find it difficult to isolate flavour,” Peng says.

“But they were very good at imagining texture, almost consistently.”

She says that distinction is scientifically significant because different sensory aspects of food may play different roles in appetite, cravings and decision-making.

While the study was relatively small, Peng hopes it will help researchers better understand overeating, dieting and why some people appear more susceptible to food cravings than others.

“The next step is understanding what the brain is actually doing and how our bodies influence our thoughts,” she says.

“I think that could lead to a better understanding of why some people are more susceptible to overeating, and why some people are more susceptible to eating disorders.”

Assessing the relationship between food-related mental imagery and appetite - Maggie Hames, Jessica C McCormack, Reece Roberts, Jamin Halberstadt, Charles Spence, Mei Peng - Appetite