London 2 Paris - By any means necessary

How in hell can you have FLAB if you are training 250km a week..?
I take you guys are all riding CARBON? one thing I don't get about carbon bikes is this
Normal steel bikes come in a multitude of different sizes to fit the exact dimensions of the rider
Carbons come in small medium or large
I have had enough trouble figuring out the right size in steel
So how do you size a carbon?
Also are carbons like really fast

I eat 250 donuts a week and drink 250 pints a week. My fat no go nowhere!
There's probably a greater range of carbon frame sizes out there now than steel.
'Normal' steel bikes come in your standard 50, 52, 54, 56, 58cm just like carbon bikes.
They don't make piddling little variations just for a laugh. My S-Works is available in 49, 52, 54, 56, 58 and 61cm. With seat, stem, bar, crank changes this range should suit 95%+ of riders.
Each manufacturer might have different TT lengths or maybe do a 55 instead of 54 or blah blah but steel frames and carbon frames are the same regarding sizing - buy one with the components that make it fit.
Steel might be easier when building a fully custom frame but I've never ridden a custom built frame of any material and I don't plan to.
Good carbon frames are like really fast, yes.