I told more or less everyone - just because our office is a very tight-knit environment, and I wouldn't have been able to hide it.
I also needed to explain to my friends that I wouldn't be drinking or joining in with any meals for a few months.
To be honest, I was expecting a bit of a backlash from people, but everyone has been brilliant about it. I think the trick is to understand the diet and how it works, so when people ask questions you've got all the answers.
I found that people were inquisitive rather than critical, and to be honest I did get LOADS of questions, which meant that I found myself repeating myself over and over to different groups of people. I didn't mind that because it helped people understand what I'm doing and why I can't have "just one treat" or "just a couple of drinks".
Once I explained that I would be getting all my RDAs, and told them all about ketosis, and the expected weight losses etc, everyone reacted really positively. It was a case of "rather you than me, but good luck to you".
I guess I'm lucky really, because I know that a lot of people get loads of flack when they tell the people around them.