Beatrice Finkelstein, a nutrition researcher at Wright-Patterson Air Force Base, conducted a series of "dark-isolation studies" during the 1950s. Subjects were placed for periods of 6 to 72 hours in a totally dark, sound proof chamber furnished with a bed, chair, refrigerator, and chemical toilet.
The purpose of this was to find out how astronauts might react to being confined in a small, dark space for a prolonged period of time. And in particular how their responses to food might change.
Some of her results:
Food has had varying degrees of significance. Some subjects have spent excessive amounts of time eating, nibbling, or counting food; others have become very angry with the food or very fond of it. Here again, evidence is strong that food in a situation of stress may be used as a tool to obtain personal satisfactions.
But the stranger result was how the lack of visual input completely changed the flavor of the food:
Palatability and acceptability of food in many instances are contrary to that on the ground or in the air; e.g., brownies have enjoyed only a fair degree of acceptability whereas ordinarily they are highly acceptable; canned orange juice usually rates low in acceptability; in isolation it has moderate to high acceptability. Data also indicate that the ability to discriminate one food from another within the same food group is impaired. All meats taste alike. Subjects are unable to distinguish one canned fruit from another. White, whole wheat, and rye breads used in sandwiches are similar in taste. Thus it is quite apparent that removal of the visual cues ordinarily associated with eating interferes with the taste and enjoyment of food and therefore the acceptability of food.
More info: "Feeding crews in air vehicles of the future"
Beatrice Finkelstein (source)