We already know our crippling cheese addiction was contributing to a growing brie belly but now we'll have to add diminished brain function to the list of side effects as well. Researchers in Australia believe they've found a link between diets high in sugar and fat and a decline in cognitive abilities. After placing rats on a steady diet of McRibs and milkshakes—or whatever the lab study equivalent might be—they noticed that within just six days the critters suffered from impaired memory.

"Poor diet was associated with a cognitive decline that happened very quickly," lead researcher Margaret Morris told the Australian Broadcasting Corporation. "We were surprised at how fast it was." The scientists noticed inflammation in the hippocampus, the section of the brain related to memory formation and storage. Within six days, the animals "performed less well on a spatial memory task," which indicated that the inflammation was "probably highly relevant for the cognitive decline," according to Morris. This doesn't bode well for the once-a-week cheesesteak diet.

Similar effects have been observed in humans including a loss of executive function, including delayed reaction time, after just five days of eating junky foods. This could have serious implications, especially as humans age and other factors contribute to memory loss and general cognitive decline. Further studies are needed to determine if improving one's diet to a so-called "optimal diet" can result in memory improvements. That's if you can manage to quit your french fry diet at all.