I presume you mean Woet Poels, who won yesterday's stage of the Tour de France?
Yes, the immediate change in cycling after there was really good epo testing, and blood transfusion testing, was that top cyclists got thinner - a lot thinner.
The Sky team were probably the first to see it, and if you see photos of Wiggins from 2011 (when he was tipped to win but fell off) and 2012 you will see he looks anorexic - very much different to how he looks now and the period beforehand. That's what all that 'jiffy bag' stuff was about, and the increase in use of inhalers, as there was talk about them being useful in weight loss. Not that I think we'll get to the bottom of all that. Likewise, Froom and Poels looked the same in this era.
Back to Wout Poels, he's too tall to be a natural top climber (1.83m is his quoted height) so he appears to have chosen to stay ridiculously thin to be able to ride as well as he does. He must be close to the end of his career now, so it will be interesting to see what he looks like in 5-10 years time.