Fasting will diminish his sexual power

Bukhari: Volume 3, Book 31, Number 129: Narrated 'Alqama: While I was walking with 'Abdullah he said, "We were in the company of the Prophet and he said, 'He who can afford to marry should marry, because it will help him refrain from looking at other women, and save his private parts from looking at other women, and save his private parts from committing illegal sexual relation; and he who cannot afford to marry is advised to fast, as fasting will diminish his sexual power." Bukhari: Volume 3, Book 31, Number 127: Narrated Abu Huraira: The Prophet said, "Whoever does not give up forged speech and evil actions, Allah is not in need of his leaving his food and drink (i.e. Allah will not accept his fasting.)"