Fasting: Should I Obey a Doctor Who Forbids Fasting but Ignores Islamic Law?

Practical Laws of Islam as per the teachings of Imam Khamenei

Fasting: Should I Obey a Doctor Who Forbids Fasting but Ignores Islamic Law?

English:

Question #751:

Since some physicians are not aware of Islamic laws, should the patient obey a physician’s order if he forbids fasting?

Answer #751:

If the physician’s statement makes the patient confident that fasting is harmful for him or he fears of harm in fasting — either on the basis of the physician’s statements or on some other reasonable grounds — then it is not obligatory for him to fast; rather, it is not permissible.

-Imam Khamenei, Practical Laws of Islam, Importance and Conditions of Fasting