This is a great question! Let me give you a few points that will help you answer this question.
First, of course the most obvious definition of gluttony is the desire for the excess of food and drink. It is the inability to moderate oneself. It is rooted in greed and shows the lack of self-control. No wonder that gluttony is one of the seven deadly sins.
Second, if we are a little more sophisticated in our thinking, we will realize that gluttony is really an issue of the heart, that is, it shows that the heart has inordinate desires for things. When we look at it from this perspective, we can say that there is gluttony for quantity, but also gluttony for quality. The same heart is present. From this perspective, a person who only loves the "finer things" of life would also be gluttonous.
For example, C. S. Lewis, the great scholar and philologist, says of this topic:
“One of the greatest achievements of the last hundred years has been to deaden the human conscience on the subject of gluttony, so that you will hardly find a sermon preached or a conscience trouble about it in the whole length and breadth of England. This has been largely affected by concentrating all our efforts on gluttony of Delicacy, not gluttony of Desire.”
Succintly put, Gluttony is defined as consuming more food than is required for one to sustain life. E.g Overeating.