Hey TT - have just read through your diary and wanted to say congrats on doing so well - the first week really is the hardest and once ketosis arrives it gets a heck of a lot easier!
Re the diet coke - you're not back to day one at all as you've still only had 600kcals for that day so it would be impossible NOT to lose weight. Citric acid also only affects ketosis for some people - for me personally I can drink diet coke and it doesn't make any difference to ketosis or weight loss so I have one if I'm out and that's all that's on offer. You just need a bit of time to figure out what works for you, and please don't beat yourself up over tiny slip-ups (which we all have made and will continue to!) - you're only human
Re AF - exante does some seriously funky stuff to your cycle and quite quickly. In my 5th week I had breakthrough bleeding on the pill (which I've NEVER had in the 10+ years I've been on it) and managed to convince myself I might be pregnant due to implantation bleeding. In the end my period then came and was really heavy (much more than normal). That said, lots of people seem to fall pregnant while doing a VLCD (think all the extra vits and decent nutrition might have something to do with it, as well as the extra *ahem* bedroom energy some get while exante-ing - you've gotta do something with your time when not eating right?
![Wink ;) ;)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
) so it's worth keeping that in mind. My own experience is that contraception is still effective but my periods are different. Based on others' experience it seems that if you're not trying to conceive but not using protection, you can fall pregnant quite readily on a VLCD.
Phew - I'm sorry - didn't mean to end up writing such an essay!!!
Wishing you lots of luck for tomorrow, and I'll look forward to hearing about the results of your week 1 WI.
xx