100 lbs to lose

This group appears to still be somewhat active:

https://community.myfitnesspal.com/en/group/15651-lets-lose-100

Another good group that's active is one for people who have or had 75+ pounds to lose:

https://community.myfitnesspal.com/en/group/15651-lets-lose-100

You can take a look at those, join if they look like they might be helpful.