I didn't want to tell a lot of people that I had joined Weight Watchers online. It seems that once you tell people you're trying to lose weight, you get all sorts of unsolicited comments or advice. I suppose it's not unlike any other major life challenge. When we were struggling with infertility having many miscarriages, I remember one well meaning woman who said to us, "Well, we believe in siblings." Um, OK, thanks.
That's really the only answer you can give, for the intent behind the words really is good will, even if the delivery doesn't make it that apparent. A smile, and a thank you, accomplishes exactly what you'd like it to. It shuts them up. Sometimes, too, the uncomfortable silence that follows the thank you is enough to give them time to think about what they said.
We all put our foot in our mouths occasionally, so it's easy to forgive these little snippets. We can't take them to heart or dwell on them. And it's in your best interest not to make it a big deal. I've found that what I've thought about myself at my lowest points, is usually worse than anything anyone else can say to me. As far as any of the advice, it's usually quite laughable. What's important is that you take from it what you need and toss out the rest. Everyone's weight loss journey is different. If there was one well meaning comment or solution that would work for all, we wouldn't be where we are today.
Taking a little time to play with words, to play with food, and just to play!