Experiments with mice suggest that fatty foods can cause inflammation in the hypothalamus of the brain. It’s an area that helps to regulate hunger and thus body weight; Isaac Asimov called it the “appestat” and suggested that fat people were hungrier people.
Brain, showing hypothalamus from "Gray's Anatomy"
(from Wikimedia Commons)
Here’s the article: “Could obesity change the brain?” Inflammation is seen after one high-fat meal. It does down after a week or so, but then a month later it comes back and persists for many months—a long time in the two-year life span of a mouse. Does it change the mice’s appetites? I’m not sure. Michael Schwartz, a professor and director of the Diabetes and Obesity Center of Excellence at the University of Washington, says “This might reflect fundamental biological changes in how the brain works that help explain why it’s so hard to keep weight off.” The research was published in the Journal of Clinical Investigation (J Clin Invest. 2012;122(1):153–162. doi:10.1172/JCI59660).
It’s also possible that obesity, a longer-term exposure to fat in the bloodstream, causes persistent inflammation, as found in earlier studies of obese lab animals. Exactly what does this mean? The researchers are now looking at NMRI scans of obese humans and finding have inflammation of the hypothalamus.
Inflammation in the human hypothalamus: A, normal weight; B, obese.
(from JCI article)
It’s suggestive that some of the best diets reduce the amount of fat eaten and gradually reduce the craving for fats.
Further research is definitely needed into diet, brain reactions, and appetite.