Believers’, fasting is decreed for you as it was decreed for those before you; perchance you will be cautious (Surah Al-Baghara, 183). The Holy Prophet (SAW) also stated: “Fast and stay healthy”. Islamic fast is an exquisite and especial method for proper planning to develop mental and physical health in fasting person. Fasting for a month , especially in the Holy Ramadan , is the specific model for twelve month of life that can insure the health of fasting person for one year , because researches show that biological clock of the brain needs to be adjusted , annually. According to the Holy Quran introductions and the traditions of Holy Prophet , the biological clock of the brain should be adjusted within this month , since in this Holy month the doors of God`s mercy are open to his servants , and implying the specific model in this month may cause physiological and psychological coordination. Hence, biological clock of the brain will be adjusted by fasting and energy turns the light of physical and mental health for the next eleven months. Evidences Acquisitions: Reports over the last decade show that any change in the lifestyle of patient can accelerate the treatment progress. Results: Although Islamic fasting is not in available in all religions, the principle of fasting exists in all religions which represents the domination of documented procedures on the human nature. Results of the current study showed that Islamic fast can be considered as the best model to improve physical health and relaxation; and reduction of crimes and violations in this month is derived from the relaxation that is naturally resulted from the adjusted basis of physiological and psychological homeostasis. Conclusions: Personal and psychological arrangements can play an important role to adjust strong homeostasis in the physiological systems. This stable procedure or homeostasis helps physiological procedures to be stable and integrated even if any problems occur, and physiological stability cannot be replaced easily by pathologic factors; hereby the illness is prevented. Regulating the release of brain neurotransmitters, hormones secretion, and metabolic processes are the most important achievements of Islamic fasting that result in mental and physical health.