I am admittedly taken aback by the 'we normally eat as a family at 8pm' posts.
I shovel food at my teenagers by 6pm. Increasingly, they'll be doing their own thing (& are very good at letting me know).
By 7pm, I'm either back at work, if the endless marking back up requires it, or if I've decided to take a night off, I'll have my feet up & be watching a movie. I'm definitely not going to be providing dinner by this point - usually there'll be leftovers they can microwave.
Either way, everyone is ideally in bed by midnight.
I don't get how a lovely civilised 8pm dinner translates into downtime after dinner, a decent night's sleep & getting up by 6 or 7 for work/school. At least two of us in my family (teacher, IB Y13 student) are regularly zonked out cold by 8pm.
I agree it's a nice time to eat. I'd definitely do that on holiday. I'm a bit surprised that it's a routine for dc in term time.
But I'm sticking to my original point: this is the age when they hang out with different families so you just go with the flow. & yes, if in doubt, feed them.