wow, I am not overweight, but it is heartbreaking hearing you and other moms who are say that this is how people treat you because of it. just know that not everyone is that self-absorbed!
I get self-confidence issues at times and when I ran into this quote, it made me feel better.
"You'll worry less about what people think about you when you realize how
seldom they do." ~David Foster Wallce. Infinate Jest
As far as being snubbed... just give them their space and ignore it. Do not give them the power to make you feel that way. like the party, you brought things, you signed up, you know you contributed... and other moms know too. I can guarantee you these women will back stab the wrong woman one day who will expose them... if it hasn't happened already.
There was a post awhile back on here asking how many moms had best friends... very few actually did, myself included. Maybe you can take a step back and try less on impressing others and more on making yourself happy. People pick up on that over time. Also, take in interest in people... ask them questions, it's amazing how much people like to talk about themselves!
Perhaps you could find a new church home?