Hi Mazz
I'll deal with the easy question first...look in the recipe section for some good under 500 calorie meals!
Headaches are very common in the early days of fasting. There seems to be a few possible reasons for them. Not drinking enough is one, but you say that you are drinking plenty. There is speculation that if you are drinking a lot (and weeing a lot of course) you might be losing too much salt. Some people find that having a cup of Marmite/Bovril/Oxo, vegetable stock or Miso soup helps with this (not too many or you get very thirsty). Another cause of headaches is low blood sugar. When you first start fasting your body may be resistant to switching into fat burning to supply your energy needs, this results in low blood sugar. As you continue with the regimen, your body gets much slicker at switching into fat burning and so the headaches stop.
If you are still getting headaches despite drinking enough and having a salty drink, we need to ask why your body is not switching into fat burning. It could be that spreading your calories over the day is preventing the switch, or it could be that having a lot of high carb/sugar foods on feed days (or on fast days) is not helping.
So, a plan of action could be: first, try a salty drink occasionally, if that doesn't help, avoid high carb or sugary foods on fast days, if you are still having problems avoid high carb or sugary foods/drinks (including fruit juice) in the last meal before your fast day (helps to kick start the fat burning mode).
And, take a couple of paracetamol to deal with the headache until you get used to the regimen. You don't want to be taking paracetamol every fast day though so you may need to reevaluate if you are still getting headaches in a few weeks' time.
Hope that helps!
