"Data" confirms what I'm pretty sure is obvious to anyone who has ever hosted and scheduled meetings in America: if you want attendees to participate productively, hold them in the late morning. They'll still be bright-eyed and bushy-tailed, but will be settled-in and focused. The creators of Boomerang, a scheduling app for Gmail, sound like they'd know: "Myth #1" is that "People hate Monday mornings for meetings"
We crunched some aggregated, anonymized data from Suggest Times, Boomerang's feature for ad-hoc meetings where the host selects the times they want to offer to their guest. We looked at a data set of over 3.5 million proposed meeting times around the globe, with most Boomerang users meeting at times that coalesce around the typical 40 hour, Monday to Friday 9am–5pm work week in their local time.
If you ask them, they'll pick afternoons, well after lunch, on days later in the week. But these meetings are the worst. They'll either be tired and waiting for the day/week to end, or busy and needing to get back to whatever they want done by 5 p.m.
All that being said, if your work gatherings involve people doing anything like what's depicted in the stock art used for this post, that's a terrible meeting, even if it's at 11 a.m. You might be in a cult? Or the last scene of a 1980s cartoon?