Many Vocaloids have a favorite food, decided by the fans (though on at least one occasion there was a contest to decide it). The most famous is Hatsune Miku's, whose character item is leeks/negi, which was the result of that one video. You probably know which one.
Kaito: Ice cream
Kagamine Len: Bananas
Kagamine Rin: Mikan oranges
Megurine Luka: Tuna
Kamui Gakupo: Eggplant
Gumi: Carrots (and at times rice lunches)
SF-A2 miki: Cherries
The UTAU also have these, notably baguettes for Kanane Teto and cucumbers for Sukone Tei.
Kid Rock manages to work in a reference to shrimp at least once an album. ("Devil Without A Cause" had one practically every other song.)
Barenaked Ladies has a running theme of Macaroni & Cheese (Kraft Dinner) to the point that they were often pelted by it.
The Beastie Boys mention White Castle a lot especially on their earlier songs (Licensed to Ill alone featured a reference to the burger joint on every other track).
Starting with the film UHF, "Weird Al" Yankovic has been known for his love of Twinkie-Weiner Sandwiches (a Hostess Twinkie split down the middle with a hot dog inserted and topped with Cheez Whiz). Since becoming a vegan, Al has switched to tofu dogs.
In The Weird Al Show, Al's favorite food is apparently jelly bean-and-pickle sandwiches.
Captain Beefheart with "Abba Zaba", based on his affection for the peanut butter filled taffy of the same name.
The Supremes, in "Buttered Popcorn," sing about a boyfriend who likes it "for breakfast, lunch and dinner too." note This is one of the only songs that featured Florence Ballard on sole lead vocals when the group was still a quartet.
In one interview Duran Duran lead singer Simon Le Bon gave in the early 1980s (i.e. from 1983 or earlier), he confessed to being partial to orange-colored Smarties (the British kind, a variant of regular M&Ms). One big fan took note of it and sent him many tubes of nothing but orange-colored Smarties, which he munched on during another interview. In a separate interview at around the same time period, Nick Rhodes stated that he adored strawberries and champagne.
Rush drummer Neil Peart is apparently quite fond of In-N-Out Burger; not only does he have a sticker of the logo on the side cases of his motorcycle, he credits the use of a Bible verse in a song to not just the original verse, but an In-N-Out milkshake cup. (Other favorites he's mentioned include cherry pie and potatoes in every way, shape, and form. There's also a FunnyOrDie sketch wherein the band gets upset at two fans [the main characters from the film I Love You, Man, in fact] faking backstage passes and sneaking into their green room after the show. What pisses Neil off the most? They ate his sandwich.)
Ozzy Osbourne said in I Am Ozzy that when Black Sabbath started touring in the United States, he took a liking to pizza. At least once, his wife Sharon has had to warn people to keep him away from McDonald's because of his addiction to Big Macs, and on The Osbournes, he demonstrated a love for burritos and carrot cake. Parodies like depicting him as having a taste for, of course, bat heads. His trademark favorite food seems to change about once a week.
Swedish electronic music duo Dada Life have a thing for bananas.
The Thin White Duke, David Bowie's 1970s persona, allegedly subsisted exclusively on red bell peppers, milk and cocaine.
Everyone in Aborted loves guacamole, and Danny is apparently unparalleled at making it. Additionally, Mendel apparently cannot resist ice cream, while Sven has an inordinate fondness for Voodoo Doughnut and makes a point of stocking up whenever he's in Portland, not that the donuts last very long.
Tendon Levey and oatmeal. In a comment from May 2017 he claimed to have eaten "an estimated 11,000+ bowls of oatmeal since 2009". To do that he would have had to have eaten almost nothing else in these eight years. note Justified in that he suffers from a throat disorder known to increase the risk of choking, making oatmeal a safe choice.
Hobo Johnsons's songs frequently mention his love of sandwiches. They even came out with official Hobo Johnson merch adorned with sandwich images.