How does one squash desire? Lets first summarize a bit of what we know about desire. Desire and motivation reside in the primitive part of the mind, below unconscious and conscious. These tend to rise after thoughts. We also know "that thinking make it so" when we are talking about the mind. So if I do not consider the possibility of "x, a concept", then there is no desire and no motivation toward that "x, a concept".
So how does this really work? In the Stoic concepts, the things not up to us are considered to be "indifferents". We do not care about them, we cannot effect them, it then makes no difference to us. OK. That may take some getting used to. Those indifferents can further be divided into preferred and dispreferred. Consider health, if we have it, it may be preferred, if we do not have it, health becomes just a indifferent, we do not have, and stop considering it something of value to us in the now. This is a breakdown of the acceptance process. Stop valuing, stop desiring.
So how does this apply to food. "I do not even considering eating anything after my portion", it stops becoming a possibility, the desire stops. Well, thinking makes it so, or at least in the world of the Stoic philosopher.
But what do I know?