When people try to lose weight, often times they begin to obsess about "the scale" and take measurements multiple times per week or even every day. As a general rule this can be a very self-destructive process. Media and specifically television shows such as "The Biggest Loser" focus on fast weight loss using what most experts would call extreme measures. What most people don't realize is that people who are morbidly obese have a lot larger cushion for weight loss than most of us, even those of us classified as obese. Expecting 3 or 4 or more pounds per week weight loss is unrealistic in the extreme. Occasionally you may see those numbers on the scale, but generally the numbers will fluctuate, and some weeks may even see a gain in weight. In my humble opinion, the only way weekly weight loss measurements are effective are if you can add them to a continuing monitor strategy and look for longer term trends. I recommend 1 month at a minimum. If you take 4 or 8 measurements over a month, and the trend is consistently sloping down, chances are you're doing things right and should continue on the path. If your trend is static, or upward, then you should adjust and compensate. Other than that, weight loss is a relatively poor measure for short period accuracy.
I generally advise clients to use something termed on many weight loss and nutrition sites as Non-Scale Victories (NSV for short). A non-scale victory can be anything from an exercise performance increase, to a size of jeans you wear. It can be an instance where you resisted the temptation to eat a cookie at a company gathering, or maybe hitting the 10 minute mile mark on a run. A weight loss strategy that tracks both weight loss and non-weight loss progress is the healthiest way to gauge progress. If you have a trainer or someone who you work with for dietary information, you should work with them to clearly state and write out your goals, including the goal, a timeline for completion, and a method to achieve that goal. Your goal should be precise, and can have smaller "waypoints" to help you track progress in smaller, more manageable chunks. Make sure your goals are challenging, but also achievable, it’s perfectly fine to ask others if they think your goal is achievable. Sometimes choosing our own goals can be a little daunting. Make sure you don't make your goals so long term that you could procrastinate, and make sure you don't set open ended goals (I.E. "My goal is to be in a size 6." This has no timeline, and no strategy for completion.). An example of a solid goal is as follows: "I would like to drop 4 inches from my waist within 4 months by eating a healthy diet with a moderate deficit, and by exercising 3 to 5 times a week for at least 30 minutes. I will track my progress by using a tailor’s tape measure every other week and record the results in my nutrition notebook." Here you have a challenging but reasonable goal, a timeline with which to achieve that goal, and a basic strategy to follow.
Setting goals is a way to help you keep to a plan, it can hold you accountable if you choose to share that goal to others, encourage those you trust to ask you about your progress, and don't be afraid to adjust your goals "on the fly" if you realize you made a goal that was overly challenging, or maybe a bit too easy. Have a lot of goals, you may or may not reach all of them, but that's not important, the important part is being accountable to something, and learning how to celebrate your victories, and stay on the right path.