We are often told not to go to the supermarket on an empty stomach.
Findings from a new University of Otago – Ōtākou Whakaihu Waka study potentially explain this theory, revealing that the way we think about food changes if we are hungry or full – not just whether we want food, but how vividly we can imagine it.
Led by PhD candidate Maggie Hames, the study found that imagining food is easier, faster and more vivid when people are hungry, which could help to understand food cravings and eating behaviour.
Associate Professor Mei Peng
Co-author Associate Professor Mei Peng, of Otago's Sensory Neuroscience and Nutrition Lab, says this shows our food thoughts are not random or purely psychological – they are closely connected to the body.
"In certain bodily states, such as hunger, imagined food experiences may become more vivid and more rewarding, making food feel especially tempting," she says.
"This may have everyday relevance for understanding food cravings, dieting habits, and healthy eating."
Giving into food cravings can substantially add to a person's energy intake, so knowing how the brain and body interact in these moments may help us better manage eating behaviour, Associate Professor Peng says.
About 60 people took part in the study, which was recently published in the journal Appetite.
They were asked to imagine the smell, flavour, and texture of food when they were hungry and when they were full to see if these imagined sensory experiences changed with metabolic state.
"It seems intuitive that food thoughts might become stronger when we are hungry, but this study tested that idea experimentally."
Associate Professor Peng was surprised to learn that it was easier for people to imagine the texture of a food rather than the flavour.
"We often think of flavour as central to food reward, but our results suggest that texture may be especially accessible in mental imagery," she says.
"At the same time, hunger changed flavour imagery but did not affect texture imagery in the same way.
"This distinction is scientifically interesting because it suggests that different sensory aspects of food may be represented differently in the mind and may play different roles in appetite, craving and food decision-making."
*The study is part of a collaborative Marsden-funding project between Otago and the University of Oxford.
Publication:
Assessing the relationship between food-related mental imagery and appetite
Maggie Hames, Jessica C. McCormack, Reece Roberts, Jamin Halberstadt, Charles Spence, Mei Peng
