This does not work. I am 15 1/2st and classed as obese according to the unreliable BMI, even a top rugby player who is pure muscle can be classed as obese, and I can easily fit into any train seat without affecting other passengers so here I think you are talking a load of tripe....sorry, but you annoyed me with this comment.
I was narrower when I fat than now I've lost weight.
My belly went outwards. I've lost size by taking up rugby and regular gym work. My belly has mostly gone - still a bit there, but my chest and shoulders have expanded massively. My waist has lost around 10-12 inches.
I was 24 stone roughly this time last year (I weighed myself shortly after Christmas last year and thought some expletives), but could easily fit in one seat on a train back then, I'm now around 18stone and can't so easy fit in one seat as my upper frame has bulked out so much in muscle.
I now have problems at shoulder height especially on 3 2 layout seating on 150/1s which was a problem I never had when I was fat.
I got big by poor life style, I've been fortunate I had the motivation to reverse that poor life style and got back into sport. Early 2015 I was walking everywhere, hours on a slow treadmill at an incline, by July I was able to participate in rugby training, and was fit enough to manage to play a match by end of August.
My back ache, knee ache and ankle aches have all pretty much disappeared and I am a far happier person.