Be aware, this story is "utter shite", Ed.
Even the most normal size people hate the thought of entering a bog on a plane or train, they stink!
However, people who enjoy fast travelling and, very much fast food before boarding and, on board (cheap airline snacks are especially delicious; AAAGH!), tend to be traumatised even more because a train, plane bog was only meant for the undernourished.
In addition, farting on a plane / train bog can also be rather embarrassing, thin walls. But nothing compared to fatties getting stuck on a stinky bog after depositing yet another junk snack.
Virgin (do they exist?) stewardesses and stewards on planes have had special training with sumo wrestlers in Japan to prepare them for worst case scenarios and, if fatties get stuck on a stinking bog on a train, conductors just pull the emergency cord because train delays are so common in the UK, nobody will notice the difference!
Modern train builders are making the things so fast and have decided to not build bogs any more because the journeys from A to B take less time and, as for train snacks, companies are stopping selling them as a gesture to the rest of humanity.
As for planes, the problem of fitting fatties in bogs is slightly more complicated. However, one Irish airline owner (he will remain nameless) has come up with a brilliant suggestion to make even more money: Passengers carrying too much weight will be charged extra for every kilo above 80 kilos making flying an extortionate experience so there will be no need to make their bogs bigger. A 'win win' situation and, even more chance of winning than their scratch card experiences!