"Please put The Biggest Loser and women's magazine covers out of your mind; losing "thirty pounds in thirty days!!" is not only irrational for most people, but very unhealthy. You should not be trying to lose more than 1% of your body weight per week. You're doing it right.
Weight fluctuates because scales measure everything, much of which can change from day to day. A scale doesn't measure just fat -- it measures everything in you and on you, including but not limited to bone, muscle, organs, muscle glycogen, water, waste, hair on your head, toenails, etc. A normal, healthy person's weight WILL fluctuate from day to day, and sometimes it may seem like a wild ride. If you've had a lot of salt, you can retain water and "gain" pounds in a single day. Good news is: you'll lose that "weight" as soon as your hydration rights itself. You need to concentrate on trends over time, and not get too hung up on day to day. As long as things are more or less trending downward, you're doing just fine. Weight loss is not a smooth progression downward. Examined over a course of months, it will look like a more or less downward trend, but it will spike upward and downward on the way. As I like to say, the line looks more like a snake than a slope, and sometimes it even looks like a sidewinder. Totally. Normal.
You can reduce some fluctuation by weighing at the same time and in the same condition. Many people here weigh first thing in the morning, after their first trip to the bathroom, unclothed. It doesn't really matter when you do it, but try to keep things consistent. If weighing every day freaks you out, then don't do it. Only do that if you enjoy gathering data and can keep the ups and downs in perspective.
Don't be taken in by the people who think the measure of success is how fast you can lose weight. Fast weight loss is not good weight loss -- and fast weight loss is often followed by regaining the weight. If what you are doing is a TRUE lifestyle change, then small changes over time, resulting in small losses over time, will add up to big things in the long run. By the time you reach your goal weight, you'll be completely trained in how to live as a thinner person. If a magic unicorn waved his hoof in your direction and you were immediately 120 pounds, you would have no idea how to stay at that weight and Mr. Unicorn really didn't do you any favors (let's assume the unicorn added a magic tummy tuck in there too, but you get my point). Use this time to learn to live a healthier life.
As long as the weight is going down, don't worry about how fast it goes. Some weeks you'll seem to lose nothing, and then you may seem to drop a whole lot the next. Weight loss goes in fits and starts, not a smooth progression. Your body has a lot of adapting to do. Don't ask it to do too many things at once and you'll have a sustainable way to reach your goals.
And really, what you are trying to do here is lose fat, not weight. It's a subtle difference, but an important one. Water weight? Who cares ... doesn't really matter toward your health. Muscle? You definitely want to eat enough to support your muscles, because if you're undereating and lose muscle instead of fat, that's bad news for your metabolism. It might help to get a scale that measures body fat percentage as well, and track that along with weight. Also start keeping a log of measurements -- waist, hip, bust, upper arm, neck, thigh, wrist, etc -- because sometimes the scale doesn't move but measurements change."
-Barb F. from the LoseIt Message Boards