Is sugar in mead different from "regular sugar"? My understanding of the process of making mead is that you combine honey, yeast and water in an anaerobic environment. The yeast-bacteria ferments the sugar in the honey and produces ethanol (among other things?). If this is true, how come labels for mead still list e.g. 90g of sugars per litre? If I'm consuming mead, am I really consuming 90g of regular sugars as found in fruit, candy etc or is this some variant of sugar that is chemically different (sugar alcohol?) in a significant way such that traditional advise "eat less sugar" do not apply?
Honey usually contains mainly naturally occuring glucose + fructose, with ratio typically 100:104-170. Sacharose occurs as well, but in minority.

Fermentation consumes just part of sugars, but that is not limited to mead. It applies to beer,wine, and bases for spirits as well.

E.g. typical "future beer" before fermentation has sugar content  $\pu{100-120 g/L}$.