I mentioned on another forum but I am going to put it again here. I know Emma Morano ate 3 eggs a day. Christian Mortensen and Walter Breuning drank boiled water. Salvatore Caruso drank water from a special fountain and ate low protein diet. And Kane Tanaka liked coca-cola and other fizzy drinks. 

In the case of my great-grandmother, she didn't like fishy food, so she didn't eat fish at all, and she didn't eat or drink milk, cheese, or yogurt because she didn't like the smell. And she never ate natto, a well-known health food in Japan, because of its strong smell and stickiness.
Instead, she ate boiled soybeans for protein and had a diet centered on vegetables. She also liked meat, but she only ate a lot when we did yakiniku (like BBQ) sometimes. She liked instant food, so she often ate instant food such as cup noodles and boil-in-the-bag curry for lunch.
She didn't eat anything she didn't like, but she didn't depend on her favorite foods either. Even if many of her favorite manju and sweets were lined up in front of her, she only brought one to her mouth.

Augusta Giontella (ITA, 1912-2022) and Lucia Laura Sangenito (ITA, 1910-Living), in their lives, have always eaten a lot of vegetables that they theirselves grew in their vegetable garden.

Maria Virgínia Pestana (POR, 1899-2010) has eaten only soup, fruits and milk since the age of c.86 until her own death.

A Decana de Coimbra Page 4 https://www.bing.com/search?q=a+decana+de+coimbra&cvid=97b88959ea2b4450973fae01c8f42e37&aqs=edge.0.69i59j0j69i57j0l6.1777j0j1&pglt=2083&FORM=ANNTA1&PC=ASTS (PDF)

Maria de Jesus (POR, 1893-2009) avoided eating meat, preferring to eat fish and vegetables. She also liked to eat Portuguese rice pudding "arroz doce".

World oldest woman dies aged 115 after only visiting hospital once | Daily Mail Online

Maria Dolores Ferreira (POR, 1902-2013) and Maria da Encarnação Sousa (POR, 1909-2022) always had a glass of wine with the meal. Maria da Encarnação drank wine from the Vila Nova de Tazem wine cellar. Maria Dolores also liked to drink her daily coffee.

https://www.cmjornal.pt/sociedade/detalhe/festeja-os-110-anos-em-familia-com-video

https://www.cmjornal.pt/sociedade/detalhe/morreu-encarnacao-sousa-a-mulher-mais-velha-de-portugal

My great grandfather (Dec. 1909 - Jan. 2020) liked to eat lots of unique foods. I can verify this because I would visit him at least once a week. Some of his favorites included Head Cheese, Beef Tripe, Pico de Gallo with Jabanero Peppers, Black Sausage, and this kind of jelly made out of boiled pig skin.

He also liked lots of junk foods, as I remember many weekends my dad and I would show up to his house with fried chicken and donuts from fast food places. And he often had pizzas, and other restaurant food delivered. He had a sweet tooth as well, as whenever we would bring him a box of donuts, he would often finish the entire dozen in 2 days. He would buy this type of Mexican sweet bread and go through a small loaf by the end of the day.

He also would drink a beer every morning at 5am, and another beer half an hour before lunch. 

Beer at 5am😀

@aquanaut_chalk Who was your supercentenarian relative?

I found some more info on the diets of some Supercentenarians. Juan Vicente Pérez Mora drinks Colombian liquor every day, Fusa Tatsumi likes to snack on peaches, plums, and grapes, Tomoji Tanabe enjoyed the occasional meal of fried shrimp, Susie Gibson likes to eat at restaurants, Joan Riudavets-Moll eats a Mediterranean diet and likes olive oil and sun dried tomatoes, and Nellie Wright who lived to 109 (almost 110) ate a British snack called "Jelly Bellies". Mrs. Wright joked that she ate so much, she practically "lived" off of them. I think it's a British term for Jelly Beans. I also remember reading a few months ago that a Supercentenarian woman ate ice cream every day, but I cannot remember her name, or find the article. Hope this helps!

Lucile Randon (1904-2023) had foie gras and baked Alaska on her 117th birthday:

https://www.telegraph.co.uk/news/2021/02/11/foie-gras-baked-alaska-birthday-feast-117-year-old-nun-survived/

She also enjoyed chocolate and apparently drinking a glass of wine every day.