Why do certain religions fast?

I wasn’t raised religious and I can’t imagine going any long amount of time without food. Why do some religions make people fast?

some religions make you fast for a few reasons. one, fasting can be good for the body, like a clensing process, and also, it is to provide food to those in need . (like you fast and give money that you otherwise would've used on food to the church, and they give the money to the poor and needy)

Here is a quote from my religions website. "To fast is to go without food and drink voluntarily for a certain period of time. Fasting combined with sincere prayer can strengthen us spiritually, bring us closer to God, and help us prepare ourselves and others to receive His blessings."