The BBC documentary convinced me and I dove right in.
In early May 2013 I was 108Kg (1.93m tall) and as I write this I'm 98Kg. I work from home at a standing desk so I'm not under any social pressures to eat at lunch with co-workers.
I still have 27.5% body fat, down from 29.9%. I plan to re-evalute things when I get near 15% body fat (such as dropping to 5:2). My goal is 83Kg which is the last time I had 11% body fat in my early twenties.
I'm currently changing what I eat as well, I do binge a little on my fast days but I have already transitioned to Almond milk/yogurt as a replacement for milk and I stopped all sodas cold turkey (wasn't a big soda drinker to start).
White sugar is out, I use honey.
Anyhow, the question was about 4:3 — personally I like it very much and now look forward to my fasting days.