For reference, five cigs or one sweatshirt can be bought for one pack of ramen, which is worth roughly $5 in prison terms. Inmates will also use packs of ramen to buy fresh veggies stolen from prison kitchens.
But this research isn't entirely breaking new ground, as the phenomenon already has its own decidedly passionate subculture. Ex-con Gustavo “Goose” Alvarez's 2015 book Prison Ramen is entirely dedicated to ramen behind bars, featuring former and current prisoners' anecdotes and recipes -- like "Ramen Goulash," and "Ramen Nuggets" -- as well as entries from celebrities like Slash and Shia LaBeouf (who are pretty much always on the verge of being arrested, themselves).
Overall, it's a bleak reality for sure. Prisoners are so underfed that ramen noodles, the lowest, most wan option on the college food pyramid, are more highly valued than cigarettes, which are literally addictive.