Self-Interest and Profit

What is beneficial to one is in one's Self-Interest, and food that suffices to replenish energy and quell hunger pangs is beneficial to one. If so, then, eating more than enough, in the absence of a storage organ, is not only not beneficial, but is likely harmful. Thus, eating an excess of food is not in one's Self-Interest, nor is the excessive acquisition of any item of use. So, at minimum, in a transaction, the increment between breaking even and turning a profit is not necessarily beneficial, and, hence, is not necessarily in one's Self-Interest. That the identification of Self-Interest and Profit is widely taken for granted is no argument to the contrary, rather, the dogmatic insistence of it only tends to confirm the diagnosis that Greed is a deeply entrenched malignancy in Capitalism.