Now that Rolling Stone has airbrushed Al Gore’s excitement away, we should all pause and reflect on which President (past or present) would have needed the most airbrushing.
I vote for Lincoln - he probably had Marfan Syndrome, and besides, well, you can just tell.
Damn! I thought this was going to be about general physical largeness and I was going to trot out my Taft fat jokes. 
Well, I’ll tell my (supposedly told by Taft himself) story anyhow. Before Taft was President, when he was a lawyer, he went to a podunk town to argue a case. When he was done, he had several hours before the next train was scheduled to stop at this little town. Optimistically, he went to the station anyhow and asked the station agent if there were any trains set to come through the station soon. He replied that there was an express due in about an hour, but it never stopped there. So Taft asked “Would the train stop for a large party?” Well, charter business is something no transport company is going to pass up, so the station agent said that the train would stop and went to make the arrangements. To the surprise of the townspeople, the express that always flew through town at 60 mph stopped at the little station and the conductor stepped down, looking for the charter group he was told would be boarding his train. Taft walked up with his luggage and said “You can go now. I’m the large party you’re expecting.”
What does this have to do with the “largeness” of the OP? Well, it took big cojones to pull the stunt that Taft did. 