Note: If you're going to be eating a meal soon, you might not want to read this question, and you (especially) might not want to click through to the "Secretive food concocting" Wikipedia article. Why? Lest you lose your appetite. Instead, you might want to bookmark this question and read it later.
Here is a question about "secretive food concocting".
The anonymous author of the Halacha For Today blog writes:
It is imperative to eat with Derech Eretz, in a dignified way.
According to the Rambam (Sefer HaMitzvos, Lo Ta'aseh 195 [in English]) and other Poskim, eating in a non dignified manner may be a transgression of one or more biblical transgressions. (See Aruch HaShulchan Siman 157:1 and Elya Rabbah Siman 170:23 what he quotes from the Shl"a.)
Neither the blog nor the Rambam nor any of the other poskim mentioned talk about secretive food concocting. But some of them do encourage every Jew to eat in a dignified manner.
Edit 1: Other sources also discuss ideas which may be relevant.
Edit 2: "One is forbidden to eat any food that most people find disgusting even if one happens to enjoy it. Foods which most people do enjoy though a significant minority of the population will consider disgusting may be eaten." —R' Ari Enkin. "Disgusting Behavior".
Edit 3: "Rabbi [Yehuda haNasi] said: What is the proper path a person should choose for himself? Whatever brings glory to himself [before G-d], and grants him glory before others." —Tractate Avos 2:1. Probably translated by R' Dovid Rosenfeld.
Imagine an imaginary young man named Reuven. Sometimes, when he's alone, Reuven likes to eat bizarre food concoctions. To see some examples, hover your mouse over this spoiler box:
• A bowl of corn flakes and barbecue-flavored potato chips with milk.
• A sandwich made of bread, hummus, and soy sauce.
• Or an entire meal made up solely of peanut butter (eaten from a plate using a spoon).
In Reuven's case, this "secretive food concocting" isn't a sign of any serious eating disorder. True, Reuven is a bit overweight, but he doesn't suffer from anorexia or bulimia. He just likes odd food combinations sometimes.
For the purposes of this question, let's define "secretive food concocting" as the eating of food combinations which would make the majority of observant American Jews lose their appetites.
I propose that perhaps secretive food concocting is undignified and therefore not a good thing for an observant Jew to engage in — even in private. So:
Is there any halachic problem with Reuven's secretive food concocting?
Even if there's no halachic problem, does the Torah nevertheless discourage the behavior?
It would be good if you could please cite decisors who have ruled directly upon these matters. If no such rulings exist, please look into the poskim and tell us what you yourself think.
I thank Double AA and especially DanF for helping me solidify my question.