Curse your lack of downvote buttons, HN.

What a terrible article. Clickbait title, super obvious answer that everybody should've learned in middle school, some nontruths (some mass does get converted to energy. It's a negligible amount (as E=mc^2 and c is big) but it's definitely not "so wrong")

TL;DR your body produces energy by converting the "weight" to CO2 and you breath it out.

This is funny: "It Gets Converted to Energy (So wrong. Law of Conservation of Mass)"

Anyone other physicists around? =)

It's correct, mass is conserved in chemical reactions. The energy doesn't come from converting mass, it comes from rearranging atoms in molecules (which releases chemical energy).

well, to be very technical about it, when you release energy in a chemical reaction, you DO lose a tiny amount of mass, according to E=mc^2. However, the change in mass is very small in a chemical reaction, as the energy released is very small in comparison to the total energy of the system (given by E=mc^2).

Ok, I should have said that matter is conserved, because that's what the author is really talking about (even though he also calls it mass).

In any case, mass can't be converted to energy either because mass already is energy (that's what e = mc^2 means).

If you don't poop it out, why were my poops 2-3x as voluminous when I was on a weight loss regime?