Oh yes people do treat you differently.
As a kids entertainer it is really uplifting hear a child announce at the top of his voice at a party "The magician is FAT" when you first walk in. That I could cope with...it's the judgement in the adults' eyes I hated. He couldn't be any good if he is that size. Before I began my performance I was starting miles behind a regular bodied performer. I had to work twice as hard to get the audience on my side. Since I've lost the weight I find the audience more "there for me" when I begin. Also adults are more friendlier and talk to me more at kids parties. I'm also taken more seriously by adults - my adult party bookings have greatly increased...I guess the skinny guy is more acceptable as entertainment (same act...different size!). The only down side is that some kids are more afraid of the magician now (adults telling them "he will make you disappear"

)...fat people are viewed as less threatening.
In "civilian life" I'm taken more seriously as well. I'm not "invisible" to the public. People tend it discount those that don't look "normal". Someone in a wheel chair was commenting about that on TV yesterday...how people would address his wife a question about him rather than talk to him - yet he is right before them.
Also the way people put you in a box is awful when you are very large. I remember being seated in a plane once (aisle seat) and an older couple were shown the seats next to me. Boy, you should have seen their faces...eyes rolling and brows knit...this lump of lard was going to take up all the space. As it was I crunched myself into the smallest place that I could - keeping as still as I could yet the man without a second thought took up all the space he could (including our shared armrest and more!). In the end he fell asleep with his head pushed near mine and his arms and legs sprawled all over my seating area - and he snored!
I dress much more stylish now than I use to. Finding good clothes that look decent on you and don't cost an arm and a leg probably helps matters along. People are very superficial...they much rather judge a man by his clothes rather than the content of his heart.
Kim