all initial assessment data are baseline data to know where you start. The importance if body weight is relative. I would consider the percent of body fat more important.
To some people this is a very sensitive issue. If the disclosure makes a client very uncomfortable then just do without it.
I agree with Karin that the importance of body weight is relative. It is a good starting point for those clients who need to lose weight, but some clients are uncomfortable weighing in. In cases where I feel the client is embarrassed or uncomfortable, I also just leave it out.
I always respect the client’s decision…