Why couldn't this sort of thing be invented?

A way to eat food and then suck it out either in stomach pump sort of way or
some sort of implanted tube drain. They give people colostomy's. The problem
with throwing up is that stomach acid erodes structures that shouldn't come
in contact with them like the esophagus, bronchi and teeth. The device I
imagine would ensure that stuff never comes in contact with sensitive
structures. Food could be eaten and then removed cleanly.

To get a feeling of fullness low calorie and no calorie fiberous materials
could be ingested in capsule and food form. Veggies and pure fiber capsules
taken with water. The result would be having your cake and eating it too.

Of course this sounds somewhat horrific, but we're already moving towards
food with no calories. Products like Olestra and Alli let you eat without
absorbing. Z trim is fiber without calories.