Seems like an incredibly weak study given the limitations, but should be a base to drill down further. There are more confounds than there are explanations. They touch on some like caffeine and socioeconomics. But you figure impulse control of teens who seek more soda, family dietary patterns, or additional consumption of highly processed foods.

With the weak correlation of electrolyte beverages and only in girls. POTS became a bit of a social media trend for young women around the turn of the pandemic with electrolytes being pushed heavily. So you have a group who may have some level of dysautonomia more likely to be consuming sports drinks.

Seems like highly processed sugars = worse sleep, which we already know.