Celsus, Med. proem 4:
From that same author [sc. Homer], it is possible to learn that at that time diseases were attributed to the wrath of the immortal gods, and that help used to be sought from them. And it is likely that with no remedies for adverse health, nevertheless their health was generally good because of their good morals, which neither idleness nor luxury had corrupted.
Eodem uero auctore disci potest morbos tum ad iram deorum inmortalium relatos esse, et ab isdem opem posci solitam uerique simile est inter * nulla auxilia aduersae ualetudinis, plerumque tamen eam bonam contigisse ob bonos mores, quos neque desidia neque luxuria uitiarant.
Seneca the Younger, Epistulae 95.18-19:
People used to be immune from those ills because they had not yet caved into pleasures, because they were in charge of themselves and took care of themselves. Their bodies hardened from necessity and true labor, fatigued by running or hunting or turning up the earth. They partook of those kinds of food that wouldn’t be possible to enjoy except for the starving. Thus, there was no need for such great medical instruments nor so many implements and containers. Health was simple for a simple reason. Many dishes makes many diseases. See how many things luxury–that ravagress of land and sea–mixes together, all just to go down a single throat!
Immunes erant ab istis malis qui nondum se delicis solverant, qui sibi imperabant, sibi ministrabant. Corpora opere ac vero labore durabant, aut cursu defatigati aut venatu aut tellure versanda; excipiebat illos cibus qui nisi esurientibus placere non posset. Itaque nihil opus erat tam magna medicorum supellectile nec tot ferramentis atque puxidibus. Simplex erat ex causa simplici valetudo: multos morbos multa fericula fecerunt. Vide quantum rerum per unam gulam transiturarum permisceat luxuria, terrarum marisque vastatrix.
Galen, Comm.Aph. XVIIb.41 K:
It used to be true in the time of Hippocrates that eunuchs didn’t suffer from podagra, but that is no longer the case now because of the excess of leisure and intemperance of regimen.
τὸ μέντοι μὴ ποδαγριᾷν αὐτοὺς ἐν μὲν τοῖς καθ’ Ἱπποκράτην χρόνοις ἦν ἀληθὲς, ἐν δὲ τῷ νῦν οὐκέτι, διὰ τὴν ὑπερβάλλουσαν ἀργίαν τε ἅμα καὶ ἀκολασίαν τῆς διαίτης.
Oribasius [?], Libri incerti 22.13 (113.30-35 Raeder, on signs of conception and regimen, dubiously attributed to Galen):
Most of all, it’s important to be on guard against abundances and to not become careless with physical labor. This is why a female servant and any other poor woman gets pregnant easily, gives birth easily, and makes a big and nourished child: because she doesn’t get soft in her regimen—it wouldn’t be possible for her to get soft while she’s serving–nor does she overconsume food.