Hrm. That really varies... There a few age-related groups if that's your thing. Everyone's welcome in the 100lb club even if you have less to lose. If you'd prefer a smaller group there are many in the Misc. Clubs area under Support groups.
There are also threads under specific plans if you'd like to chat with people following the same routine.
Then again, if you're just looking to chit chat there's a general chatting section
Post anywhere you're comfortable! Everyone is welcome all over.