Gluttony is a state of desiring to stuff oneself somehow. Who does that harm?
If it is a mere impulse, no one. If it is a prelude to obesity and beyond, it may harm the perpetrator and tangentally his friends. It may even be deadly.
But only when gluttony does result in harm is it evil. Merely to have a gluttonous thought is harmless.
It is not hard to imagine the results of gluttony through temptation to action to a sense of addiction — a formidable closing of ones freedom to determine one’s destiny. But even in one whose external circumstances are not optimal for the exercise of freedom, the main hope continues to lie in the freedom that remains within the inner space occupied by will and conscience and the values that determine the disposition of the heart.
When this freedom is evoked, one can reject a temptation and begin to imagine a different course. Our society would improve if this understanding underlay the mentality of those who are paid to counsel persons with harmful addictions. Nothing is more powerful than the will that is freely engaged in a beneficial act.