O chastity, how greatly thy beauty shines, in sleeping on the ground, and in hunger pangs that drive away sleep through the body’s hardship, and through abstinence from food which produces a deep moat between the ribs and the belly! All food and all leisure that we indulge in create and give birth to shameful images and unseemly idols, and these come forth and are beheld in the hidden place of our minds, enticing us secretly to take part in shameful deeds. But an empty stomach makes our thinking a desert land, arid and silent from any turbulent thought. The stomach that is filled to satiety is a place of spectacles and an arena of vile fantasies, yea even if we be alone in the desert. For, it is said, satiety desires many things.

—St. Isaac the Syrian

Another spends all he can rap and run on his belly, to be the more hungry after it.

In Praise of Folly, Desiderius Erasmus

St Maximus speaks very clearly to the issue:

The following four things are said to change the body’s temperament and through it to produce either impassioned or dispassionate thoughts in the intellect: angels, demons, the winds and diet. It is said that the angels change it by thought, demons by touch, the winds by varying, and diet by the quality of our food and drink and by whether we eat too much or too little. There are also changes brought about by means of memory, hearing and sight-namely when the soul is affected by joyful or distressing experiences as a result of one of these three means, and then changes the body’s temperament. Thus changed, this temperament in its turn induces corresponding thoughts in the intellect.

Mental Disorders & Spiritual Healing: Teachings from the Early Christian East
Jean-Claude Larchet

Gluttony is an emotional escape, a sign that something is eating us.

—Peter De Vries

…or is it they who are sober and vigilant, and limit their eating by their need, and sail with a favorable breeze, and find hunger and thirst the best relish in their food and drink? For nothing is so conducive to enjoyment and health as gto be hungry and thirsty when one attacks the viands, and to identify satiety with the simple necessity of food, never overstepping the limits of this, nor imposing a load upon the body too great for its strength.

…For it is not the nature of the food, or of the drink, but the appetite of the eaters which is wont to produce the desire, and is capable of causing pleasure. Therefore also a certain wise man who had an accurate knowledge of all that concerned pleasure, and understood how to moralize about these things said “the fall soul mocketh at honeycombs:” showing that the conditions of pleasure consist not in the nature of the meal, but in the disposition of the eaters.
Therefore also the prophet recounting the wonders in Egypt and in the desert mentioned this in connection with the others “He satisfied them with honey out of the rock.” And yet nowhere does it appear that honey actually sprang forth for them out of the rock: what then is the meaning of the expression? Because the people being exhausted by much toil and long traveling, and distressed by great thirst rushed to the cool spring, their craving for drink serving as a relish, the writer wishing to describe the pleasures which they received from those fountains called the water honey, not meaning that the element was converted into honey, but that the pleasure received from the water rivaled the sweetness of honey, inasmuch as those who partook of it rushed to it in their eagerness to drink. Since then these things are so and no one can deny it, however stupid he may be: is it not perfectly plain that pure, undiluted, and lively pleasure is to be found at the tables of the poor? whereas at the tables of the rich there is discomfort, and disgust and defilement? as that wise man has said “even sweet things seem to be a vexation.”

A Treatise to Prove That No One Can Harm the Man Who Does Not Injure Himself
St. John Chrysostom