I realise you asked your question days ago, but I've only just read it so ... I've done IF (intermittent fasting) for a while now and it works for me. I don't do a strict 5:2 though and I don't think you have to. Instead, on fasting days, I will skip breakfast, have a very light snack mid afternoon and regular dinner at about 6. I do this 2 or 3 days per week and manage it easily. I also don't eat much carbohydrates (sugar, bread, pasta etc) as this makes it easier to go a long time between meals. There's an article in next week's Radio Times which is really helpful and gives detailed advice. Hope this helps!