Updated

Is it a deterrent against bad behavior, or a way to keep weapons out of the hands of violent inmates?

Some prisons are serving inmates Nutraloaf, a blocky mash of ingredients that provides all the nutrients growing convicts need to thrive — and can be eaten without a fork or a knife.

Nutraloaf debuted as a punishment. Prisoners who throw food, utensils or even bodily fluids at guards and other inmates can see their regular prison fare replaced with the unsavory loaf, which some find so disgusting it’s incentive enough to behave.

Recipes vary, but common ingredients for the jailhouse block include bread, cheese, fruit, vegetables and beans, and just about anything else.

Now some prisoners are arguing that Nutraloaf isn’t just gruel, it’s cruel — and they’ve brought their case all the way to the Vermont Supreme Court.

It may be unappetizing, but is it illegal? FOX News conducted a taste test at the Epicurean Culinary School, an elite academy in Hollywood, where students were told that what they were eating was the newest "it" food in L.A. The bread may not look like haute cuisine, but it is healthy and high in protein, and made with no additives.

Could Nutraloaf be the next California superfood?

Reviews were mixed: One student thought it had a texture like gum, "sticky and strange."

"I don’t hate it, but it would be good in an emergency," another said. "The texture is really odd, and the flavor is super-bland," said Dan Orell, a chef at the school. "It tastes like a pile of canned spinach."

After the taste tests, FOX News revealed the truth: What they were eating once was called "confinement loaf" when it debuted in the '70s and had been banned in several prisons.

The apprentice chefs concluded it was disgusting but hardly illegal — and most were happy it was being served to convicts. "It’s definitely punishment," one student said. "I wouldn’t give it to the dog."

But could it get rowdy inmates back in line?

"This would work as a good deterrent," one chef-in-training said. "I think this would be like 'Scared Straight.'"

William Lajeunesse contributed to this report.