It's not easy to handle the looks you get from other people when you are carrying hundreds of pounds. Especially if it's an extended stare, a disgusted look or followed by an innocent comment from child to parent about why you are so big....I think I've seen it all. But at some point, you move from seeing it and being embarassed, to ignoring it or not even seeing it all.
I've had the "talent" of ignoring for a long time. I knew I did this, because I've had to explain it to friends I've been walking with - when THEY start to feel uncomfortable. (A little experiment sometime - walk a few paces behind someone whose overweight...and observe other people as they pass by, I'm guessing you'll get to a count of 10 looks within a one block radius).
I was recently reminded of this again when I was walking around with a black eye for two weeks (minor surgery, everything's fine). The interesting thing was, I didn't notice those stares, unless someone asked about it because I was so used to blocking things like that out so it didn't get to me.
If you are in that situation, whether you're the person being stared at or you catch yourself doing the staring, there's one thing to do that makes a world of difference. And that's a smile and a hello.
Instead of letting feelings of insecurity take over, turn it into something positive. Break the awkward moment and shift everyone back to the human element. Show them it's not just fat walking around there's a person in there too - and do they probably have a story to tell! We all do. Shape, size, color, or age. On the street or in the gym.