Emerging evidence in humans suggests a typically Western high-fat, high-sugar 'junk food' diet can quickly undermine your brain's appetite control.
After indulging in a week-long binge of waffles, milkshakes and similarly rich foods, researchers in Australia found young and healthy volunteers scored worse on memory tests and experienced a greater desire to eat junk food, even when they were already full.
The findings suggest something is amiss in the hippocampus - a region of the brain that supports memory and helps to regulate appetite. When we are full, the hippocampus is thought to quieten down our memories of delicious food, thereby reducing our appetite.
When it's disrupted, this control can be seriously undermined.
Over the years, extensive research on juvenile mice has found the function of the hippocampus is very sensitive to 'junk food', but this has only recently been observed in young and healthy humans.
In 2017, after a week of Western-style breakfasts of toasted sandwiches and milkshakes, researchers found participants performed worse on learning and memory tests which are typically dependent on the hippocampus.
Now, in this latest study the team has found that not only do such high-fat, high-sugar diets impair memory in humans, they also appear to directly affect our ability to control our appetite.