As for new badge ideas, you could do some related to the forum in general. you could also do 5lb mile stones, instead of just 10. For those members who are loosing weight, but at a much slower rate.
Badges for app (if any) being used, badges for folks on a specific diet type (not sure what the diets are exactly, but I know they exist), badges for line of work folks are in (if they volunteer that info), bages for users who admit to using a specific device type (smart scale for ex), badges if a user does a mile mark exercise (walks a mile for ex), badges for number of times an exercise is done (walked a mile for 7 days in a row, for ex).
These are what I can think of, off the top of my head. Hope they help inspire some of your own creative juices.