The following quote from Charles Washington says it all for me.
This is the most frustrating aspect for me trying to run this type of forum. So many people think that the answers lie in Science and perhaps it does. However, we know that science and the results can be easily manipulated in such a way that every conclusion is ambiguous. ZC is all about experiencing it on the individual level. We are our own control group so you can't come in here and tell us how it doesn't work or what science says based on some results concocted in a laboratory or some metabolic ward. We are science, we are evidence and we are history. Our experiences mean everything. We've done it (or are doing it) and that is the most important factor.