Should I use a scale...before...after the gym? what is my real weight.

When should I weigh myself? I'm 5'4,5'5ish....when I wake up in the morning i'm usually around 111.....after I go for a run 8 miles I'm usually 108-109....and at the end of the day 112-113.....I know this is a bit obsesive but I'm just wondering when I should weigh myself.  I just want to make sure my BMI is healthy. 

By the way...are scales even a good idea or should i throw it away? I dont want to lose anymore weight I just want to maintain..... I find I'm becoming  obsessive with it....weighing myself too often...but I'm worried if i throw it out I might balloon out because I'm not keeping tabs on myself.  Does anyone have any tips?   It took me a year and a half to get from 140 to my weight now...I don't want to go back to that....

Your weight is going to fluctuate not only throughout the day, but from day to day.  The human body retains water - we're made up of 75% of it.  Pick a time to weigh yourself every day, under the same conditions, and record your weight here on the site.  The best time is in the morning, when you first wake up, without any clothes. 

You point out that after running you weigh less - that's because you've been sweating.  Don't fixate on the number.  Look at the trend line.  That's a moving average taken of the last several weights.  As long as it continues to drop, you're losing weight.  If it continues to rise, you're not losing weight, and you need to reduce your caloric intake.  3500 calories per pound, so to lose a pound a week, cut 500 calories from your diet.

Weight maintenance is not visualized with daily snapshots.  You need the daily data, but you should only look at your progress as an analysis of the week's or month's worth of data, focusing on the trend line.

You Should only weigh ONCE A WEEK! under the same conditions, there is no point weighing every day as it will go up and down depending on loads of factors, what is digesting, water even clothes. so just do it one day a week naked at the same time of day each week.

weigh yourself everyday after you wake up and go to the bathroom.  That's what i do...this way, if my weight does change throughout the week, I see that. 

Weighing yourself once a week works in theory but what if you happen to hop on the scale the day you're at your heaviest.  I would rather go in knowing that my weight will change everyday...but still know what it is.

I"m a once a week weigh in girl.  Every sunday immediately after I wake and go to the bathroom.  I think it allows me to  catch anything before it gets to out of control.

This week I only lost .6 lb.  I was able to regroup and hopefully I'll be back to to my 1.8-2lbs weight loss.

I weigh myself once a day in the morning before I get in the shower. Last week I was about 159-160. This week I am about 158-159. So I lost about a pound. I enter my weight on this website almost everyday. Then you can really see the difference as it graphs it out.

Your weight will fluctuate throughout the week and throughout the day. So you should weigh yourself at the same time everyday as well. Let's say you weighed yourself on Sundays. It is possible that Sunday was your heaviest day of the week and it seems you gained a pound that week when you really are down one.

Seems like from what everyone is saying, that how often and when is a personal choice.  The important thing is to pick a time and/or day and be consistent with it.

there is no such thing as "real weight."  the best you can do is be consistent: same scale, same time, same conditions (pre/post meal, exercise, etc).  and even if you're perfectly consistent, there will be fluctuations.