I think 'ramen profitable' is a great pithy phrase, but to work long hours effectively (and stay healthy) it always struck me as a false economy to live on rice & beans. Good to see some data on the topic.
I don't know much about nutrition, but I was under the impression that noodles, rice, and beans are all high in starch, which the body turns into significant amounts of glucose in a healthy way (sustained blood glucose over time, instead of short spikes like with simple sugars). I'm sure surviving on Ramen is bad for you, but as far as this article is concerned, it will help you have self-control.