I found doing the first TT contest that I was becoming obsessed by the scales and even got to a point of weighing myself sometimes up to 4 times a day!
I gave up on the weighing thing and found it very helpful. This time out, I weighed myself on day1 to give a starting point. A couple of weeks later, I felt I'd lost some weight and was intrigued to see if I'd dropped below 200lbs so I weighed myself. (198.5lb - hurrah!) and I weighed myself after my birthday weekend (to see how much damage I'd done!)
When I weighed myself regularly, I was constantly tinkering with what I was eating, how much I was exercising - I got to a point where one week I probably ate only about 4000 calories - I almost stopped eating just to get the dial to move down (and I felt like crap too!) After getting a right bollocking from Sue (my wife) I realised how obsessed I'd become - I'm not very good at moderation - and so I aimed to weigh myself only every 4 weeks. I'm a bit more balanced in terms of my weight now but I still need to avoid obsessing about weight and just trust in the process.