Dwindling food portions and less meals per week have led more and more prisoners to resort to buying ramen noodles from commissary.
Although ramen prices in prison are not the same as Walmart. It is almost twice as expensive, and it has replaced cigarettes as "prison currency". Inmates need to cover the need to eat, while tobacco is considered a luxury. They exchange ramen noodles for other necessities such as toothpaste or other food.
Read more at "Forget cigarettes -- there's a new prison currency" - Via: CBS news