[QUOTE=John Mace]
Depends on the food. To get even more gross than Sam Stone, ever notice some identifiable bits in your poop? You didn’t get any of those calories.
[/QUOTE]
There’s no calories in them to get. Or at least, none that our digestive systems can get. We aren’t “equipped” to digest certain parts of plants, like cellulose. A cow, on the other hand, can, thanks to it’s multi-chambered stomach and chewing it’s own cud.
[QUOTE=Quercus]
It’s probably accurate to say that it does, but only a tiny bit of the matter.
[/QUOTE]
No, not even a tiny bit of mass is converted to energy. Combustion is a chemical reaction that converts one compound into another (ie, solids into gas and ash), liberating heat in the process. But the mass of the resulting gases and ash is equal to the mass of the original solid.
[QUOTE=bikebloke]
I wonder why some moon-bat hasn’t come up with a diet based on this? “Eat chalk and watch the fat melt away…”
[/QUOTE]
Or “chow down on a fistful of Tums before every meal!” Both calcium carbonate and citrate are pretty close to as digestible as the calcium in milk, so assuming you’re taking in magnesium with it, I wonder…?