It's OK to modify your fasting approach, especially as you take note of what is happening to your body. The concept is refocusing NOT hurting yourself.
Daily Discipline – The Art of Fasting

countering culture with the TRUTH of GOD's word
It's OK to modify your fasting approach, especially as you take note of what is happening to your body. The concept is refocusing NOT hurting yourself.
Fasting is often times a forgotten discipline for believers. But it is a powerful tool that helps us re-center our hearts and minds on God and helps us focus our prayers more meaningfully.
Meditation is not a bad word. I remember growing up thinking it was though. This was largely due to the New Age Movement being pretty popular and it had taken over the Biblical concept of meditation in most people's minds.
We are all likely guilty of praying to God in such a way that it becomes this one-sided conversation where we unload all our baggage on to him and ask for help and a lot more. Then, we say "Amen" and walk away without actually listening for Him to respond to us.
Meditation - it's a word that doesn't get spoken about often in the Church, largely because it has gotten a bad reputation from the "New Age Movement". But the word is used all throughout scripture, and primarily relates to an intentional focus on God, His Word (the Bible), and His works in our lives.