I'm on week 5 or 6 of a 5/2 diet. I've registered for the progress tracker but I only started weighing myself last Friday so I'm counting the start of the week as my "official" start date. I figure that since initial weight loss is so dramatic it makes subsequent weeks seem anticlimactic so better to ignore it. I do know my trousers are already noticeably looser.
I took to heart the idea that on a fast day you can ignore food so I start my fast days with a glass of milk and a vitamin pill and might have another glass before bed. Other than that I don't eat. I was never a breakfast person so I'm not really suffering. To be honest I have a hard time getting my head around the idea of eating while fasting - the milk already feels like cheating. I thought they probably included the 500/600 calories thing to avoid lawsuits. But each to their own.
I think I miss cooking on fast days more than I actually miss eating. With a regular calorie-restricted diet I'd be crawling up the walls by this stage but the thought that I'm only ever a day away from my normal grub is keeping my motivation up and I think the fast days are becoming much easier as time goes by.
I fast Monday and Wednesday, train Tuesday and Thursday and the weekend is an orgy of greasy food and alcohol.
Good times.
I'm shooting for a pound a week, so wish me luck.