Many religious customs were borne from necessity, such as Lent or no meat on Fridays for millions of Catholics. In olden times, there was a shortage of meat, so the church declared Friday as meatless days, that way the poorer populations would not be singled out for not having meat as part of the daily meals and they could offer their hardship as penance (to receive blessings).
Lent was that time of year after winter storage was running low and spring harvest was still months away. Fasting was a way to accept the hardship as an offering to please God, rather than to endure because there was little food available.