Hi Vnilla. What are you eating on your fast days? I'm not sure if this will work for you, but I make myself a HUGE pot of veggie soup (mostly broccoli, cauliflower, cabbage, spinach) and that's what I eat throughout the day. It really fills me up. I do variations of the soup to keep it interesting and sometimes have a low-ish cal snack plus soup, but the soup is my staple on fast days. Also, I tried to exercise on a fast day last week and felt quite dizzy. I know from past experiences that I'm not great on exercising when hungry. You're right, it isn't for everyone. I ended up just doing light weights and taking it easily and steadily. I also stopped when I knew that I could not push myself any more without falling over. It really is just an added bonus if you can exercise on fast days, but if you can't, it really is okay.