i think it is an excellent idea to offer to bring a healthy snack for everyone, like fruit salad or veggies and hummus. even if one doesnt need to lose weight, they need to eat healthy. talk with the girls in your group. tell them what is going on. i'm sure noone will take offense, and you might inspire people to eat better.
"Look, I've never had a dream in my life because a dream is what you want to do but still havent pursued. I knew what I wanted and did it till it was done so I've been the dream that I've wanted to be since day one.
You can dream a little dream or you can live a little dream, I'd rather live it because dreamers always chase but never get it."