Curvature
Tried looking in a couple of places including caa website, and could not find anything on BMI.
Probably not related to being a pilot, but i found this on NATS website for their controllers (who also need to get a class 1 medical)
Originally Posted by NATS careers webpage
Metabolic, Nutritional and Endocrine Diseases: Diabetes will normally be disqualifying. Obesity may be disqualifying. A Body Mass Index below 35 is a normal requirement for a Class 1 certificate.
All the best mate