This weekend in our Sunday zoom which was devoted substantially to food issues we tangentially discussed the statements that I gather are traditionally attributed to Metrodorus to the effect that the stomach or belly is of particular significance.
I thought I'd paste the following here as what appears to be the major source of this, and repeat my belief that general statements of this type should be viewed with caution. These sources (particularly Plutarch) are substantially hostile, and I am not aware of there being a direct and reliable statement of this position in a friendly source (Diogenes Laertius, Lucretius, Diogenes of Oinoanda).
At the very least I would personally put this in the category of "the size of the sun is as it appears to be" or "all sensations are true" or "the good is easy to get" or "what's terrible is easy to avoid" which require explanation by reference to other positions before the true meaning becomes clear. Without such context and explanation I personally would not cite statements to the effect that "the root of all good is the pleasure of the stomach" as an authentic statement of correct Epicurean doctrine.
I'd put all this in the context of what Torquatus says when he explains that everything is related to the body, but that the pleasures and pains of the mind can greatly surpass those of the body:
[55] XVII. I will concisely explain what are the corollaries of these sure and well grounded opinions. People make no mistake about the standards of good and evil themselves, that is about pleasure or pain, but err in these matters through ignorance of the means by which these results are to be brought about. Now we admit that mental pleasures and pains spring from bodily pleasures and pains; so I allow what you alleged just now, that any of our school who differ from this opinion are out of court; and indeed I see there are many such, but unskilled thinkers. I grant that although mental pleasure brings us joy and mental pain brings us trouble, yet each feeling takes its rise in the body and is dependent on the body, though it does not follow that the pleasures and pains of the mind do not greatly surpass those of the body. With the body indeed we can perceive only what is present to us at the moment, but with the mind the past and future also. For granting that we feel just as great pain when our body is in pain, still mental pain may be very greatly intensified if we imagine some everlasting and unbounded evil to be menacing us. And we may apply the same argument to pleasure, so that it is increased by the absence of such fears.
If someone has other cites or arguments that should be considered in this context please post.