A Universal spokesman told PEOPLE that the park has "long used" a 40-inch waist size as a general guideline, and that it is not a new standard specific to Super Nintendo World
Super Nintendo World – overview and history
Universal Studios' new Mario Kart ride ripped for rules restricting plus-sized visitors
Review: Universal Studios Hollywood's Super Nintendo World ⋆ Atomic Junk Shop
First US 'Super Mario' Theme Park To Open – Channels Television
Let's-a-go (to Hollywood)! First US 'Super Mario' theme park to open
What to do in Nintendo World at Universal Studios Hollywood - Los Angeles Times
Super Nintendo World Review: Good, Bad & Ugly - Disney Tourist Blog
How the Mario Kart Ride Works at Super Nintendo World – Orlando ParkStop
Ride Review: Mario Kart in Super Nintendo World - Disney Tourist Blog
We Went to Super Nintendo World! : r/giantbomb
Super Nintendo World: How to Get on the Mario Kart Ride Faster