Frankly, I hate weighing clients.  It's my least favorite part of my job.  I'd rather stand toe-to-toe with their eating disorder throwing a mega-tantrum than weigh my clients.  The scale often holds so much power over their self-esteem that it can determine the tone of their entire day.  It's remarkable that a number that represents the body's gravitational pull has gained so much importance in our culture. 

How the ED uses the scale:

• To measure your self-worth
• To determine your mood for the day
• As an alleged motivational tool to "keep you in line" with food
• To tell you how much you're allowed to eat that day
• To shame you
• To prove that certain foods are bad and thus shouldn't be consumed
• Basically to make you feel like crap

How an RD uses the scale:

• To assess your weight in relation to your body's historical growth patterns, current eating patterns, activity level, and medical history.  This helps us to estimate if you are within your body's set-point weight range or not.
• If someone appears to be out of their set-point weight range the question becomes "Why?"  What is going on that has contributed to this?  These become the behavioral issues to address.
• To teach clients that changes in weight from day to day, or even week to week, represent normal fluctuations resulting from fluid shifting, foods consumed, bowel/urine/sweat excretions, clothing worn, time of day, etc.  It's normal for weight to fluctuate a few pounds either direction.
• To monitor for trends in weight over time.  This gives clues to what's happening with metabolism and nutritional intake. 
• Most importantly – to demonstrate to the client that the scale is a clinical tool that can only provide a limited amount of information.  It is not useful when used as a weapon against ourselves.