IIRC it's mostly a factor for gut absorption: when gut cells absorb glucose, sodium is cotransported (goes along for the ride) and thus pass through the gut and into the bloodstream at a much greater rate, and the greater sodium gradient increases the rate of water absorption: https://www.ncbi.nlm.nih.gov/pubmed/11193601

And the sodium also (and originally) serves to combat hyponatremia, as lost fluid generally brings sodium along for the ride if you rehydrate with non-electrolytic water you find yourself with mild to severe low sodium levels.

It drove me a little bit crazy to hear a mom complaining about how she couldn't find sugar-free Pedialyte for her child. It is difficult to explain that to a person who has spent their whole adult life demonizing artificial colors, artificial flavors, and of course sugar.

If only there were Diet Pedialyte(tm)!

That explains my appetite in sweet beverages (which I normally do not drink) when having a hangover.

Same. I'm always really in the mood for orange juice when I'm hungover.

Dehydration causes sugar binges for this reason.

There's many a time, I believe, I've mistaken a loss of appetite control for some "emotional event" when it's been mere dehydration.

I recently traveled for several days without drinking much and sugar binged when getting home. I assumed the travel had stressed me, rather, I was just severely dehydrated.

The article is wrong. I moved my response to https://news.ycombinator.com/item?id=16440309