A well-known monk with a bodily disorder was the deceased Bhikkhu Buddhadasa, who was given all kinds of diets when he was alive. Buddhadasa was fat most of his life.
However, for example, some current Western monks (based in Western Australia) have put on lots of weight, which looks like eating too much rich food & doing too little exercise; devoting their lives to teaching, scholarship & administrative duties.
You reach an age when you start to put on lots of weight. You must reduce your food intake because your body obviously does not need so much food anymore.
Two years ago, I cut my life-long food in-take by 50% & stopped eating certain foods (cheese, ice-cream, bread; I never ate much sugar). I lost 12kg but notice if I eat certain prohibited foods (such as when visiting my mother), I add weight quickly.
These monks are often given lots of Asian sweets & cakes and drink lots of sugar drinks.
Years ago, I spent lots of time in a certain monastery in Asia. The last time I visited, after five years of absence, I noticed how the core monks had all lost lots of weight. Obviously, the abbot thought the monks were too fat and instructed to reduce food, for the sake of public image. Having known these monks for 17 years, I could not believe how thin they were.
Dhp 395. The person who wears a robe made of rags, who is lean, with veins showing all over the body, and who meditates alone in the forest — him do I call a holy man.