Plutarch’s Moralia, “Advice about Keeping Well”, 10
“But, just as flowers’ scents are on their own weak but when mixed with oil they gain strength and tone, so too does an initial mass of food provide substance and body, so to speak, to the causes and origins of afflictions from outside the body. Deprived of this, none of these can be severe, but instead they wither away and decrease on their own, when simple blood and clean breath meet their entry. But in a mass and excess of food, it is just like some kind of churning mud which makes everything unclear, and dirty and hard to pass when it is stirred up.
We should not, then, be just like those praised ship captains who allow a massive cargo because of greed and are for this reason always occupied baling and pouring the sea out of their ship—no, we must not stuff our body and then apply medicine to make us purge it all, but instead we should keep our bodies slim so that if ever we are depressed, our body will rise up again because of its lightness, like a cork.”
ἀλλ᾿ ὥσπερ αἱ τῶν ἀνθέων ὀσμαὶ καθ᾿ ἑαυτὰς ἀσθενεῖς εἰσι, μιχθεῖσαι δὲ τῷ ἐλαίῳ ῥώμην ἴσχουσι καὶ τόνον, οὕτω ταῖς ἔξωθεν αἰτίαις καὶ ἀρχαῖς οἷον οὐσίαν καὶ σῶμα παρέχει τὸ πλῆθος ὑποκείμενον. ἄνευ δὲ τούτου, τούτων χαλεπὸν οὐδέν, ἀλλ᾿ ἐξαμαυροῦνται καὶ διαχέονται ῥᾳδίως, αἵματος λεπτοῦ καὶ πνεύματος καθαροῦ δεχομένου τὴν κίνησιν· ἐν δὲ πλήθει καὶ περιττώματι οἷον ἰλὺς ἀναταραττομένη μιαρὰ ποιεῖ πάντα καὶ δυσχερῆ καὶ δυσαπάλλακτα. διὸ δεῖ μὴ καθάπερ οἱ ἀγαστοὶ ναύκληροι πολλὰ δι᾿ ἀπληστίαν ἐμβαλόμενοι, τοὐντεῦθεν ἤδη διατελοῦσιν ἀντλοῦντες καὶ ὑπεξερῶντες3 τὴν θάλατταν, οὕτως ἐμπλήσαντας τὸ σῶμα καὶ βαρύναντας ὑποκαθαίρειν αὖθις καὶ ὑποκλύζειν, ἀλλὰ διατηρεῖν εὐσταλές, ὅπως, κἂν πιεσθῇ ποτε, φελλοῦ δίκην ὑπὸ κουφότητος ἀναφέρηται.