Plateau
How long have you been at the same weight? How many calories are you eating and how do you split them out (3 meals - 4 meals)? How much protein to you get in? Are you lifting?
If you really have been stuck more than a few weeks at the same weigt your calories could be too low and you could be in starvation mode. You may want to try an additional protein snack at the end of the day to shake things up try to add about 250 more calories total to you day but you might want to touch base with your nutritionist on this as well.
Cottage cheese as your last meal of the day before bed is a good choice - mix in a little sf pudding of sf jam for more flavor. The casein is a slower burning protein and will burn longer through the night. It helps with the muscle recovery and it helps with preventing your body from going into starvation mode over night.
Are you really consistnt with your workouts? Are you lifting as well as doing cardio? After a long workout session its also good to add in a post workout meal such as a protein shake. Also, keep in mind that muscle weights much more than fat so if you are lifting heavy you could also be building muscle. Have you had your BF% percentage done lately?
I was stuck at the same weight for almost three weeks but I was also working out 6 days a week and eating 80 - 100 grams of protein 1200 - 1400 calories total. Doing everything right. It just happens. I ignored it. The only thing I changed was just making sure I was truly getting in 80 -100 grams of protein by documenting my intake in fitday (www.fitday.com) Just the last two days the scale is down another 3 lbs. Surgery was 4/19/05 .. started at 281 and now 225.
If that doesn't work then the next thing I would encourage you to try is kicking your exercise routine into high gear and getting in cardio 5-6 times a week and doing resistance training 3x per week. You can also try splitting out sessions. For example 30 - 45 min cardio in the am and do 20 - 30 minutes of weights in the afternoon.