Episode 548: Lent practices of St Francis DeSales - Part 1 - Fasting

If we keep in mind that fasting is simply a means and only do it in moderation and with our spiritual directors approval, then we are well on the way to enjoying the great benefits of fasting.

St. Francis lists six:

Elevating the spirits: for the same reason that eating too much makes it hard to concentrate, eating too little makes it much easier.
Keeping the body in subjection: here St. Francis is using the word “body” to refer to our bodily desires, not the body itself, which as mentioned above we generally treat poorly by excessive eating because of our bodily desires.
Practicing virtue: those who have fasted know that it can be emotional and much of virtue consists in accepting our emotions so that we don’t get caught up in them. Fasting is an excellent training ground for this.
Gaining a greater reward in heaven: fasting atones for our sins and the sins of others, thereby helping us to gain a greater heavenly reward.
Restraining gluttony: from my experience intermittent fasting, it’s easier to stop eating when you should if you know that you can fast. Like it or not, we all have a fear of being hungry and fasting curbs this.
Causing the devil to fear us: St. Francis wrote, “although we may not fast very much, yet the enemy has greater fear of us when he sees that we can fast.” Jesus said of a demon that he cast out, “This kind cannot be driven out by anything, but prayer and fasting.”