I have recently started the 5/2 diet and am on my 4th fast day. I do feel it is working though I don't think it'll be really obvious for a month or so. However, I am also doing a lot of exercise (a lot more, I should say, for me) and had until today refused to fast on my energetic days. Well today I went swimming (1.5km) and also did a lot of gardening, cleaning out animals etc on 460kcals. Despite having a healthy 'dinner' of a tomato stew, I am now starting to feel dizzy, sick, have the shakes and even a bit of blurred vision. the last 3 times I was ok, but hadn't done the exercise. Help. I am grumpy, tearful and just want to eat a big slice of toast! I won't, but has anyone any advice for getting past this 'hurdle'? Thanks.