There have been cases of very fit individuals beeing put through additional tests because they had numbers that were out of parameters, one of our pilots is an athlet and he needs to stop training a week before every medical as to not have any lactic acid in his system for example. You can be over a BMI of 30 once you are hired but if you let your weight go then there are many additional tests, we had a pilot that was walking around with a heart monitor for two days as part of his over 60 medical requirements and because he was at a BMI of 32 I believe, they failed him on his medical and the last I heard is that they will give him another go but he has to go on a diet. Over 60% for what one of the recruiters told me fail the pre employment medical check.