Snacks that are negative calories?

Jackinga went on a bit of a rant said

Over at Woot!, there is on “New Food Deals! Can someone please invent a snack that’s negative calories?”, which got me to thinking that it would take more energy to eat/chew it than it supplied.

Konjac (0.33 cals/g; dietary fiber 1.3%) immediately came to mind, though it would need a great deal of work to make it a snack, I think. Straight out of it’s watery package, it is pretty awful. Everyone knows that. But as tasteless and nasty as Konjac is, there are much lower calorie foods; though to be fair, the amount of chewing needed to eat Konjac is right up there, so it may come in actually lower than the calculated values above based on combustion measurements)

The food should probably be high in fiber, but overall chewable, which eliminates most meats. And the snack should not have been cooked as cooking helps to increase nutrition by breaking down whole unprocessed food making the nutrients within more available.

I am reminded of once giving a rabbit some iceberg lettuce. The rabbit wisely enough would have nothing to do with it.

Iceberg lettuce comes in at 0.14 cals/g and a dietary fiber content of 1.2%. A close second is cucumber at 0.149 cals/g and a dietary fiber content of 0.5%, then celery at 0.16 cals/g and a dietary fiber content of 1.5%. One could conceive that the act of chewing and the energy it takes to try to digest either one would be an overall negative, or close to it, calorie food. Food is a term, which I using loosely here.

Trouble is, I wouldn’t consider, Konjac, iceberg lettuce, or celery a snack in the sense of something that is both appealing and that tastes good.

What do you think? Got any more suggested candidates?