It turns out that our minds or how we think about our meals can influence our snacking habits.
For those struggling to reduce their snacking habits, researchers from the University of Cambridge say the “meal-recall effect”—remembering a recent meal—is a perfect way to do that.
They found that a simple imagination exercise whereby you simply think back to your recent meal and try to imagine it was a lot bigger and more filling than it actually was can help reduce snacking.
Their study revealed that participants’ imagining a huge meal resulted in them eating just 24g fewer biscuits, which translates to approximately 122 fewer calories.
“Your mind can be more powerful than your stomach in dictating how much you eat,” said the lead author of the study, Dr. Joanna Szypula. “Our findings could give people a method to control their eating with their mind.”
Szypula’s team worked to determine how recalling a recent meal and then mentally picturing the meal 3 hours later in different ways, including what it felt like to chew and swallow the food, had an effect on later snacking habits.
Researchers enrolled 151 participants and provided them with microwaved rice and sauce along with a cup of water to eat. They instructed the participants to eat the entire meal if they could but not to the extent that they were uncomfortably full and couldn’t move.
They were then to return to the lab 3 hours later to perform an imagination exercise and a bogus taste test of biscuits.
Participants were split randomly into five groups. The researchers asked three groups to try to recall what they ate back in the lab while being specific about the ingredients and the quantity when providing details of the lunch. They were also told to imagine moving the meal around the plate or that their recent meal was two times bigger than it was in reality.
For the fourth group, participants were not to remember their lunch but were given photos portraying spaghetti loops in tomato sauce (a meal they didn’t eat). They were told to scrutinize the photos for as long as they wanted and then write a little description of the contents in the photos. And like the other group, simultaneously imagine moving the food around a plate.
The fifth group performed the same task, but spaghetti was swapped with stationery, e.g., paper clips.
Next, the participants were to eat some selections of biscuits or cookies and rate their tastes based on taste attributes like salty, crunchy, chocolatey, etc.
The team informed the participants to eat as much as they wanted as it would be disposed of at the end of the experiment for hygiene reasons. But the researchers only wanted to assess how much snacks they ate secretly.
They found that those that imagined spaghetti hoops, and stationary, including those who imagined moving their meal around the plate ate the largest number of biscuits (an average of 74 g)—suggesting it did not significantly decrease their biscuit intake.
Meanwhile, those that imagined they ate a huge lunch ate the fewest biscuits (an average of 51.1 g).
The final step was to test their memory of the original size of the meal. The team asked the participants to replicate the original portion of food they ate on a plate and into the bowl given.
It turned out that the strategy worked so well that the participants reported feeling sick or disgusted. The study authors explain that making one imagine overeating food and feeling overly full induces a feeling of disgust and eventually leads to losing appetite for more biscuits.
In addition, the group that recalled the food they ate while imagining it was double the size of reality ended up underestimating portion size. This implies that while the imagination test lowered the number of biscuits eaten, participants were still well aware that the size of the food they ate was not as big as they visualized.
“More research is needed to understand how and why the meal-recall effect works,” said Szypula. “This might mean that we are able to harness the effect in a more efficient way and possibly offer valuable advice to people.”
People trying to cut back on their snacking can try tricking their brains into believing they just had a huge meal and were filled up, as this study proves the tactic to be highly effective.
But whether it can help further with weight loss also needs further investigation, the scientists say.