I started 5:2 in early March, and so far have lost 11 pounds. I was very impressed, considering the weight I was at was my absolute minimum weight since college (~10 years). My BMI was 21.7, so not bad. I was happy with my weight, just not how I looked in photos. My arms still are not coming out quite right in photos...
I'm a medical student and my busy routine during the year really helped this. Twice a week, I would eat one meal around 4pm and did pretty well with that. All of the other days I basically went to town, so people just starting out--do not beat yourselves up, the weight loss is just incredibly incremental. It will take me a month usually to see that oh yeah the scale actually has gone down 2-4 lbs.
Now I am working in Europe for the summer where there are carbs everywhere, and I don't have the flexibility with my schedule to run at the time I prefer (morning). So I've gotten really bad. However, 5:2 has still been working its magic and I have lost 2 pounds in the 5 weeks since I arrived in Europe--that had kind of been my rate of loss anyway. I even took last week to do a 5 hour fasting window every day to see if that would help, which basically amounted to an entire week off of fasting because the window thing drove me nuts . So I am happy to have maintained the 2 lb weight loss.
I feel puffy and out of shape though, and would like to lose 5-7 more pounds before a wedding in mid-August. I am going to keep fasting 2-3 times per week, and more importantly, run every off day and lift weights a couple of times a week. At the very least, I will improve my puffiness .