This is where looking at shaking things up can help. WW is great for good tips on that. ONE visit to a sports nutritionist/health nutritionist might also be well worth the $$$ (and even covered by your insurance).

Lots of people plateau. It's the body's response to all that weight loss. The answer is patience...and shaking things up. Things I've done in the past when I've hit a plateau (they don't have to be weight related..mine have come in the form of BMI, body fat percentage, muscle development, and yes, weight), is to change up my eating for a week or two (increase/decrease protein, carbs, fats) and change my workout routine. Cut back on cardio, increase weight training. Switch out what I do...both cardio and weights. If I've been running alot, I switch to the bike. If I've been doing both of those, I get in the pool. If I've been on the elliptical, I get on the stairmaster. Or I mix it all up if I've been doing too much of one thing.

Same with weights. If I've been going for more lbs added to my weight routine, I cut back and increase reps. Try new routines. Free weights vs the machines. Take a class at the gym that I haven't taken before.

How about Pilates? Yoga? Great things to add to a workout routine that won't stress your joints.