According to the researchers after only one week of eating high fat, sugar added diets the participants performed worse on memory tests and had a desire to consume junk foods following a meal.
Findings suggest that a typical Western style diet causes some sort of disruption in the hippocampus region of the brain, which is the region that involves memory and appetite control, making it harder for the participants to regulate their appetite.
“After a week on a western-style diet, palatable food such as snacks and chocolate becomes more desirable when you are full,” Richard Stevenson, professor of Psychology at Macquarie University in Sydney and one of the co-authors of the study, told The Guardian. “This will make it harder to resist, leading you to eat more, which in turn generates more damage to the hippocampus and a vicious cycle of overeating.”
For this study 110 healthy participants between the ages of 20-23 were recruited and split into two groups: a control group who ate a healthy diet; and the experimental group who ate a typical Western high energy diet which included a hearty portion of Belgian waffles and fast foods. Both groups ate breakfast at the start and end of the week, then completed word memory testing as well as rated their desire and enjoyment of high sugar foods such as Coco Pops before and after their meals.
“The more desirable people find the palatable food when full, following the western-style diet, the more impaired they were on the test of hippocampal function,” said Professor Stevenson.
According to Stevenson, when the hippocampus functions less efficiently there can be a flood of memories to the brain that make the food appear to be more appealing. Findings from this study mimic earlier research conducted in animals showing that junk foods impair the hippocampus.
Stevenson goes on to explain that although there is no definitive reason as to why this occurs, it is believed that the hippocampus blocks/weakens/lessons memories of food when we are full. Initial subtle impairments caused by the typical junk food laden Western diet may lead to long term decline in other areas such as obesity and diabetes, both of which have been linked to developing dementia and declines in brain health.performance.
Stevenson believes that due to the steady rates of increase in the decline of American health, both mental and physical, will eventually lead to forcing the government to restrict the consumption of junk foods in a similar manner as was done to smoking.
“Demonstrating that processed foods can lead to subtle cognitive impairments that affect appetite and serve to promote overeating in otherwise healthy young people should be a worrying finding for everyone,” says Stevenson.
