Soranus believed that obesity was a chronic disease in immediate need of treatment. He suggests [sic] treatment with a combination of diet and exercise, baths, venesection, purging and a radical change in the way of living.
Soranus’s suggested treatments for obesity could have been written today. (Well, except for the bit about venesection or blood-letting. But I am sure some diet guru somewhere will recommend it to combat The Obesity Crisis sooner or later.)
But they weren’t.
Soranus of Ephesus lived from 98-138 AD.
The more things change, the more they stay the same.
Some of the other treatments recommended by physicians in the Ancient world referenced in the article are:
Celsus (circa 25AD):
… states [sic] that the body may be thinned “by hot water if one bathes in it and especially if the water is salty; by bathing on an empty stomach, by a scorching sun, by heat of all kinds, by worry, by late nights; by sleep unduly short or overly long, by a hard bed throughout the summer; by running or much walking or any violent exercise; by vomiting, by purgation, by sour and harsh things consumed; by a single meal a day; by the custom of drinking wine, not too cold, upon an empty stomach”.
Oribasius (325-400 AD):
… considers [sic] obesity as a pathological condition in need of treatment through emaciation and fat reduction. He suggests altering the “temperament” from moist to warm, because the warm temperament renders the body lean. Then, exercise, diet, medications, baths, massage and provocation of “mental anxiety” may dry the temperament up and emaciate the body.
Source: Greco-Roman and Byzantine Views on Obesity. The full article is linked as a pdf from the right-hand column (NB: this article comes from the Obesity Surgery journal, so please consider the source when reading it).