I am reading a New York Times profile of Dustin Hoffman, having just finished another about a yoga instructor, the name of whom I've forgotten already. The interviewer sets the scene for Hoffman, noting the ashen sky, his tennis shoes, and that they are sitting down to lunch. Then, as an aside, we are told that Hoffman has ordered the "steak and chips". (We are in England, and so the latter is in keeping with local nomenclature.) The yoga instructor, we are told, is a vegetarian.
We are told these things, because they create the picture of the person, and serve also to confirm it. Hoffman is a an aging slice of Americana, and even when abroad, eats as such. The yoga instructor is slim, bald, and has a jarring lucidity in his eyes. We are not told of the wheatgrass drink he consumed for breakfast, or the quinoa he will have for lunch; but it is not hard to imagine.
You are what you eat.
There is a similar phenomenon regarding what you drink. It too suggests things about you, and would equally be at home in a profile. We might also be told that Hoffman ordered a beer, or that he had coffee. We can imagine him scoffing at the myriad of flavor descriptors given to the brew, satisfied with coffee being coffee, same as always. Our yoga instructor, probably, does not drink coffee. Perhaps he is worried about adrenal fatigue.
Of course, I could be wrong. But unless we know otherwise, those assumptions seem safe. Or at least, they feel right. Everything about people informs everything else about them, and the whole gives us an idea about the parts. And so we generalize, we guess, we bullshit, because that's the best we can do. And often, that does get us pretty close.
Of course, sometimes it misses wildly. But this is not about how one ought to judge a book, merely how we do. It's worth keeping in mind, that what we eat, drink, and otherwise consume creates and perpetuates who we are.