Yeshivaguy, thank you so much for your honesty. I am a “single” girl in shidduchim and am what many would consider overweight, like a size 18. I ALWAYS made sure the guy knew beforehand that I wasnt a size 2 or a size 10, because it’s NOT fun for the girl either. Throughout the years I’ve been dating, I always believed that the “right one” wouldn’t care and he would think that I am beautiful despite my weight and BH I am now dating an amazing guy who is very happy with me and my weight. I think its important that if weight is “hands down” an issue for you, then you should ask because coming from the girls side, we don’t want to date boys who are adamant about it either. But, just from a hashkafic perspective, physical attraction is one of Hashem’s ways of letting us know that its right… I don’t think people should force it, it’s not fair to either party. So if weight is an issue for you then it’s one extra way of knowing a girl is not for you.
With regards to the shadchan, I don’t think its her responsiblity since it might make the other party reconsider the shidduch when weight wasn’t the biggest issue for them in the first place. It’s up to the boy to ask and the girl (who realizes that her shidduchim come from Hashem) to request that the boy know beforehand.