Sin begins in our thoughts. It’s no accident that, at Mass during the Penitential Rite, we ask forgiveness beginning with admission of those sins we’ve committed “in my thoughts” and then we add, “and in my words, in what I have done, and in what I have failed to do.” Repentance involves thinking.
That’s the primary reason that we practice fasting during Lent – not because food is bad but because eating involves thinking and we need to pay attention to our thoughts. We think about being hungry and how to satisfy that hunger. Fasting helps us to pay attention to our thinking at a very superficial level so that we can apply that same discipline to other levels of thinking that lead to sin. It’s brilliant psychology: start at a level that we can exert some control over and then apply that control to deeper levels of thought.
All this to say that we should encourage our students to fast during Lent while helping them connect that action to their thinking and how we need to “change our mind” during Lent so that our choices bring us closer to Jesus.
Consider inviting your class to choose a time to fast in solidarity with one another in the coming week. In other words, agree upon giving up a meal on a specific day at a specific time, knowing that you will all attempt to do so together. Encourage them to do something during that time that helps them to move closer to Jesus (pray, do good works, serve others). Then, the following week, you can talk about the experience and how the discipline of fasting gives us discipline over our thoughts which leads to discipline in our actions.