Obesity is a brain disease that is only made worse by unhealthy Western diet, study said.
A person's brain retains food memories in the mind when he or she feels hungry. After eating, the food thoughts fade away so that food becomes less of a priority.
But according to researchers from Macquarie University in Australia, this natural brain process is hampered by high-fat, high-sugar and low-fruit, low-vegetable diet of Westerners.
Researchers said that sweet, fatty foods impair memory inhibition abilities of the hippocampus in the brain. As a result, the smell and sight of food trigger cravings even after eating a full meal.
"Even though they were full, they still wanted to eat the sweet and fatty junk food," Tuki Attuquayefio, co-researcher of the study, told Independent.UK.
"What was even more interesting was that this effect was strongly related to their performance on the learning and memory task, suggesting that there is a link between the two via the hippocampus."
The study, which was supported by the Australian Research Council, analyzed healthy young individuals. The researchers found that participants show often eat Western-style diet struggled to complete learning and memory tasks, whereas participants who ate healthier foods performed better.
When it comes to eating behavior, participants who eat Western diet found it difficult to stop eating even after finishing a full meal, whereas participants who maintain a fruit and vegetable-rich diet showed more restraint when offered snacks after a meal.
The study, which was presented at the obesity conference in Portugal, is the first to discover a link between food, memory and obesity in humans.
In another study presented in the same conference, psychologists from Michigan State University suggested that obese people are more likely to overeat after seeing a delicious snack or a junk food advertisement than people who are thin, Mail Online reports.
"Our study suggests both a psychological and neurobiological account for why obese individuals may be particularly vulnerable to these signals," Dr. Alexander Johnson of Michigan State University, said in a statement.