Having averaged a weight loss of about 1kg a week for the first month on the 5:2 diet I have found that since then (about another 5 weeks) I have lost only another kg in that entire time despite sticking to my two fast days, staying below my TDEE on almost every day (maybe gone over about 2 days total in the past month) and increasing my excercise in the past few weeks. Last week I burned 2500 calories extra over the week in the gym and out running and still no weight loss! I've still got another 18kg to go to reach my goal weight and whilst I don't mind how long it takes, at this rate I think it's going to take until 2020 to get there! I know people hit weight loss plateaus but everything I've read says this normally happens about 6 months in or once the person reaches a 'good weight', I'm still at the upper range of 'overweight' according to my BMI.
I think I'm secretly hoping that my body will be reading this and realise that really all the science indicates I should be losing weight and I'll step on the scales tomorrow morning having caught up and lost another 8kgs!