You give up freedoms no matter what you do, in any situation, and some would argue that any freedom we do have is an illusion - whether restricted by law (no matter how free your society, there are still things you cannot do because the law says you cannot) or by metaphysics (the theories of quantum determinism state that every action you take is determined and unchangeable).

However, if you deny determinism and accept the limits placed on freedom by law (which I am assuming this question is doing) and consider freedom in this limited sense there are some other issues to consider.

1) Legally you cannot have your choices taken away from you. You are no longer bound to a spouse 'til death do you part' and no Master has the right to limit freedom - you always have the choice to walk away. With this in mind, every freedom you lose is lost by choice - you willingly give it up.

2) I mention spouses because I would also add that I do not consider the freedoms you sacrifice in a BDSM relationship to be much different to those you sacrifice in a marriage or long term relationship. There are things I can no longer do because I am married, there are things I have to do now because I am married. I *could* choose to ignore the obligations but my personal sense of duty forbids that.

In most relationships you gravitate to a point of compromise that is acceptable to both sides. If it is not acceptable, you have two choices - adapt or leave. The main difference in BDSM is that one party can set a hard line to negate compromise and the other has to accept that or leave (less chance of adapting). However, during the initial stages of that relationship, there would (or should) have been a lot of negotiation and discussion - more than is usually seen in a vanilla relationship and certainly more formal - that should have negated the need for compromise later in the relationship. And, quite often, the so called 'hard line' is an illusion - the relationship is always adapting and most Dom/mes are open to renegotiation and the best constantly reassess the relationship and adapt where needed.

So, I would argue that you never lose any freedom that you are not willing to give up in the first place and no loss is a permanent loss, no matter what is claimed at the time.