A new report from the University of Calgary answers a question that has troubled doctors and nutrition researchers for years: "Why are people who lived through the low-fat diet craze of the 1990s immune to new dietary information?"

The report focuses on the effect of low-fat eating on the thalamus, the part of the brain responsible for updating and correcting dietary misinformation.

"We observed a behavior pattern in our lab," explained Aaron Grayson, a resident in Neurology at the University of Calgary and one of the contributing authors of the new report. "When we encouraged certain patients to increase the amount of fat in their diets and reduce sugar consumption, we received what seemed to be verbal confirmation of understanding. The problem is, these patients would continue to order low-fat vanilla latte's and choose rice cakes over almonds as a snack."

Grayson's team quickly recognized that these patients weren't intentionally being non-compliant. The patients simply couldn't process the new dietary recommendations they received from their doctors.

"It was like their brains simply filtered out anything that contradicted what they had learned about nutrition in the mid '90s," Grayson said.

The Calgary team carefully reviewed the dietary history of these patients and found they had all consumed a higher-than-average amount of SnackWells and Healthy Choice products.

"Once we made the connection, we began ordering hi-resolution CT scans of the thalamus," Grayson explained. "The results were clear: dietary fat restriction had effectively starved the brain of vital lipids, causing shrinking of the thalamus."

Grayson is optimistic that the damage is reversible but admits the process would be extremely difficult.

"Basically you just need to lie to your loved ones and sneak bacon fat and butter into their low-fat foods," Grayson said.