Mustard is at least part of what makes street food so amazing. You drizzle it on hot dogs, smear it onto pretzels, squeeze it into knishes... and while it’s something gourmets can get super snobby about, even Anthony Bourdain acknowledges that the cheapest yellow mustard has its delicious, vinegary place.
In most cases, enjoyability is a sure sign that you're eating something that's horrible for you. But the happy truth is that mustard isn’t just an ideal dressing for almost any sandwich, and an essential culinary ingredient -- it’s also totally good for you. Here's the proof.
It has serious bang for the caloric buck
At 3 calories a teaspoon, mustard is the lowest calorie of the common condiments. Compared to mayo (31 calories), sweet relish (7 calories), or even ketchup (6 calories), this stuff is basically a freebie.
It has a long history as a health food...
According to Kenneth Kiple, author of The Cambridge World History of Food, Vol. 1 -- which at least sounds about as legit as it gets -- mustard has been used for both medicinal and culinary reasons for a really, really long time. The ancient Romans used to smear the stuff on themselves to cure everything from epilepsy (note: NOPE, THIS DOES NOT WORK) to lethargy (I mean, maybe? It would probably burn a little bit, which would get you off your ass?) to “hysterical females” (headdesk).