Some people lay stress on fasting ...

“Some people lay stress on fasting. They affirm that in augmenting the weakness of the body they develop a spiritual sensibility and thus they think to approach God.
 Weakening one’s self physically does not necessarily contribute to spiritual progress. Humility, kindness, resignation, and all these spiritual attributes emanating from great physical strength are acceptable to God. That an enfeebled man cannot fight is not accounted a virtue. Were physical weakness a virtue the dead would be perfect, for they can do nothing.

 If a man be just, kind, humble and merciful and his qualities are acquired through the will-power — this is Godlike. A child cannot kill a man; but a Bonaparte can abstain from war, from shedding blood, from devastating countries. A dumb person will not speak ill of any one, a paralyzed hand cannot strike; but a strong arm can refrain from striking. Justice, love and kindness must be the instruments of strength, not of weakness.

 Exaggerated fasting destroys the divine forces. God has created man in a way that cannot be surpassed; we must not try to change his creation. Strive to attain nearness to reality through the acquisition of strength of character, through morality, through good works and helping the poor, through being consumed with the fire of the love of God and in discovering each day new spiritual mysteries. This is the path of intimate approach.”

Abdu’l-Baha, Divine Philosophy, pp. 98-99