It isn’t so much the quantity, but the manner in which we eat, that is the greatest problem for our souls. A smaller person will obviously need less food than does a larger person, so if the larger person eats a greater quantity of food this doesn’t make him a greater glutton. It is very possible the larger person, while eating a copious quantity of food, could do so in a manner, and with a spirit more focused on God, in virtue, than the smaller man does in eating his biscuit or loaf of bread.
Let us always keep God foremost in our minds, with thankfulness, as we eat our daily bread. And not eat mindlessly, simply shoveling it in without thought or gratitude, being mindful of how much is enough for us, stopping before we are filled to our limit. For even with a good mental outlook, a full belly can still be an impediment to our peaceful communion with God, instead, leading to scattered thoughts and a scattered way of living.