While memory-related brain engrams have been studied before, this is the first time researchers have pinpointed those specifically dedicated to eating
In a breakthrough that could reshape how obesity is treated, researchers in the US have identified a specific group of brain cells responsible for creating memories of meals — and possibly for triggering excessive hunger in people with memory problems.
The study, conducted by scientists at the University of Southern California (USC) and published in Nature Communications, shows that individuals who frequently forget recent meals may feel hungrier and eat more, potentially leading to disordered eating patterns.
The research focuses on neurons in the ventral hippocampus, a brain region known for its role in memory. During meals, these neurons become active and form “meal engrams” — a type of memory trace that stores detailed information about eating experiences, including what was eaten and when.
“Meal engrams function like sophisticated biological databases that store multiple types of information such as where you were eating, as well as the time that you ate,” said Professor Scott Kanoski from USC’s Dornsife College of Letters, Arts and Sciences.
While memory-related brain engrams have been studied before, this is the first time researchers have pinpointed those specifically dedicated to eating. The discovery opens new possibilities for tackling overeating and obesity — not just by focusing on diet and exercise, but also by enhancing memory formation related to meals.
Using advanced neuroscience tools, the team observed the brain activity of lab rats in real-time as they ate. These “meal memory” neurons were found to be distinct from those used in other types of memory. When scientists selectively destroyed them, rats could no longer remember food-related locations but retained normal memory for non-food tasks — highlighting a specialised neural system for processing meal experiences.
Further investigation revealed that these neurons communicate with the lateral hypothalamus, a brain region already known for controlling hunger and eating behaviour. When the connection between the hippocampus and hypothalamus was disrupted, the rats began overeating and failed to remember where meals had occurred.
The findings underscore the role of memory in regulating hunger and suggest that forgetting recent meals may impair the brain’s ability to gauge satiety, leading to excessive eating.
“Current strategies for managing weight often target food restriction and physical activity,” said Kanoski. “But this study suggests that reinforcing memory formation around meals could be just as crucial.”
The researchers hope that this new understanding of “meal memory” could pave the way for innovative treatments for obesity and eating disorders — particularly in individuals experiencing cognitive impairments or age-related memory decline.
