Italian food certainly has some flair and personality, and there's a certain stereotype of Italian chefs who are eager to encourage others to eat their food. I discuss Italian food extensively in From Marcy to Mob Wife, which also caused the woman who ate the food to become Italian herself.
Author Janno Jones added some Russian food and culture in the age progression/weight gain ebook, MILF Soup. Similar to Marcy, the young woman who drank the hearty Russian soup also became Russian as part of her changes.
French and English aren't as associated with weight gain, but they often employ foods with plenty of grease and butter, so they can certainly get the job done. They feature heavily in From Charlotte to Chavette: The Ring of Change Saga.
Usually, I don't mentioned a specific cuisine, I just note that the character is eating junk food - like gorging on donuts like in Donut Surprise, or Case Study. In Going Bananas, I go the other direction and note that the character is gaining weight despite the fact that she's eating nothing but small amounts of raw fruit.
One food that I'd like to write about more is Mexican food, both because I like it and because I think it has good weight gain potential (Mexico is the fattest nation on Earth.) It's also fun to describe as a writer (nachos!) I'm writing a scene at a Mexican restaurant in one of my current projects.
What about you? What do you think is your favorite cuisine to read about in a weight gain story context, and why? Leave a comment and let me know.