I weigh myself everyday. It keeps me accountable. When I overeat, I know it will show up the next day and having to plug it into my fitday just annoys me enough to stay on plan that day and the next and the next (however long it takes to bring it back down again). I used to get affected with the ups and downs, but then I started paying attention to the trends and noticed the kinds of foods (unhealthy) that caused those spikes and other things like stress and exercise. So in a way, I learned more about my body and I don't get affected now by the daily blips. It's the overall trend that I'm concerned with. So far, it shows a downward trend, so I'm happy.
I've weighed everyday since I joined the site in May. I am glad I did. As now, I have a very good insight on my daily fluctuations and what causes them. Therefore, when the scale is up a pound I take it in stride and keep moving forward. Weighing daily definitely works for me and keeps me on track.
I think you'll find that most people here weigh weekly, or at least record it weekly.
I weigh daily - what matters most to me is my average weight over days or weeks (since the little fluctuations are mostly caused by water weight and aren't meaningful), and having more data points just makes it that much more accurate. I log my weight on physicsdiet.com which does all the calculations for me and spits out a nice chart (I'm lazy ).
It's one of these things that you should do according to what feels right to you.
I go to WeightWatchers, so I weigh in every weight, and that's my official weight. Every couple of days, however, I weigh myself at home just to check that I'm vaguely on track.
Some people weigh themselves once or twice a day though, and some people don't weigh themselves at all. Just do whatever feels right to you.
I weigh everyday. It's not really healthy for my mental state, to see the constant fluctuations, but I like having a very complete record. And like tracking my food, I know if I skip the weighin a few days, I'll get distracted and binge and before you know it, boom, gained ten pounds.
I think it is a matter of personal preference. I weigh myself weekly. I get scale obsessed if I weigh everyday and it can start to have a detrimental effect on my weight loss efforts.
My "official" weigh-in day is Monday morning, but I weigh myself most days, sometimes several times a day, but I'm not obsessed with it. For me, its just interesting to see the fluctuations during the day or week, and I know not to take any one number too much to heart- I can fluctuate a couple pounds within a day. If I were getting stressed about the numbers, I would have to put the scale away. I'm just getting to know how my body works, and as long as the trend is downward, I know I'm on the right track. I'm less concerned about the number than how I feel in my body.
Obviously, everyone is different in this way! Be honest with yourself about what works, or doesn't.