I have to say the key I have discovered to my fasting experience has been keeping hydrated. Without liquid I fade quickly. My body is unable to cope especially in the sun with the little ball of energy.
The lesson I have definitely learnt is I need to drink more. I say this to the children all the time. However for myself I have often not had a drink for the whole day. All I can really say is Lord please help this be a permenant change and not just because it's necessary during fasting or I faint!