[dperfect]

> Wouldn't the 24 gram loss of sugar mean a 24 gram loss of mass in the candy bar?

No. That's what I'm trying to explain. Let's assume they're going to make the candy bar the same size regardless of ingredients. If sugar represents a smaller portion of those ingredients, it just means there will be more of the other ingredients relative to the sugar. You're really just adjusting a ratio of sugar to other ingredients.

Don't think of it in terms of a candy bar; instead, think of a giant vat filled with the melted chocolate that will eventually be turned into candy bars. By not adding as much of one ingredient, you're just raising the proportion of other ingredients to the total weight. Those other ingredients may be heavier or lighter than the absent ingredient, but it most likely won't just be air replacing it (they could add more air, but that's probably not necessary).

Even if the final product does end up being a bit lighter, I bet most people wouldn't care (and more people would appreciate the lower sugar content).

[pbhjpbhj]

... and you're not thinking of it like a global conglomerate board member "we've cut weights as much as we can; but we think that we can pack in some filler material or cut weight further if we sell it as 'sugar reduction' - personally I'm going to use the money to buy a second floating palace, my other one doesn't match my third wife's new tiara".

Or, they could sell the product and let people choose how much to eat for themselves? If they want to do something moralistic they could quit promoting baby formula to nursing mothers, or stop buying chocolate from places that use child slaves, or go Fairtrade on cocoa and sugar.

[xorxornop]

Except that most people have repeatedly shown they're not capable of making sensible choices. Although that's possibly a secondary/tertiary effect, seeing as how it's so hugely variable over different regions of the world