While searching the newspaper archives, I found this entertaining anecdote about Nikola Tesla working in Edison's laboratory in Paris. Mr. Tesla's ability to hyper-focus on his work and its effect on his appetite is illustrated.
Great Thinkers Are Sometimes Great
He took Tesla to a restaurant, and ordered one of the biggest and thickest steaks that could be bought anywhere. It was enormous. With it there were various garnishings, which made for the two men a hearty meal. But when they had finished it, something in the young student's look led Mr. Fulton to say: "Is there anything else you would like? You are out with me, you know, and I wish you would order anything you want." Tesla looked around vaguely for a moment, as if making up his mind, and then said: "Mr. Fulton, if you don't mind, I would like another steak!"