The English idiomatic phrase “food for thought” describes something that is intellectually stimulating, that is interesting to think about, or that has a profound meaning, which can or should be pondered at length. The use of this phrase dates back to the 1800s, but many language historians believe it was in use much earlier. If someone says that something is “food for thought”, it means they find it interesting or intriguing; it might also indicate that the speaker does not wish to draw a conclusion or commit to a position on a topic hastily.
The essential idea behind this phrase is allegorical. It’s the idea that complex problems or concepts might provide nourishment for the brain in the same way that food provides nourishment for the body. The meaning of the phrase is, on its own, food for thought as experts ponder the role of ideas and in the human brain and general human development.
While many English speakers might be familiar with the phrase “food for thought,” many of them might not use this on their own in a conversation. Instead, some common alternatives like “something to think about” may be used. The phrase is really a more colorful metaphor that is not necessary in order to convey the basic concept that the speaker is talking about.
Although the idea of “food for thought” is not entirely scientific, it does have a lot of application to similar thoughts about the way that the human mind and body work together. Experts often recommend a combination of physical, social, psychological, and spiritual wellness for overall good health. In this sense, "intellectual fodder” can be part of the total nourishment for a healthy human existence. In similar idioms, religious people often talk about being spiritually fed and even use the phrase “man does not live by bread alone” to talk about the idea that spiritual food is important for nourishing humans. The idiomatic phrase works on a similar basis, although it is usually not meant to be a description of something that is necessary for good health.
Often, speakers also use the phrase to favorably describe a piece of art. For example, someone might say “that book on social issues was really food for thought.” The same could be said about a film or any other work of art that stimulates the intellect. Alternatively, a speaker might use it to delay giving an immediate response to a proposal that involves making a major commitment, or where it might seem rude or dismissive to immediately respond in the negative. For example, a protective parent might use this phrase in response to a young teen asking permission to go on a first date, thus gaining some time to think it over.