fruits and veggies give fibre that helps keep you going, the best form that she has found is sullage
First she boiled and simmered a kettle of Sullage, a common Gorean soup consisting of three standard ingredients and, as it is said, whatever else may be found, saving only the rocks of the field. The principal ingredients of Sullage are the golden Sul, the starchy, golden-brown, vine-borne fruit of the golden-leaved Sul plant; the curled, red, ovate leaves of the Tur-pah, a tree parasite, cultivated in host orchids of Tur trees; and the salty, blue secondary roots of the Kes Shrub, a small, deeply rooted plant which grows best in sandy soil.
Priest-Kings of Gor, page 45
I had nearly stepped into a basket of plums.
Tribesmen of Gor, page 45
A guard was with us, and we were charged with filling our leather buckets with ram-berries, a small, reddish fruit with edible seeds, not unlike tiny plums, save for the many small seeds.
Captive of Gor, page 305
Laxatives
Some girls I have been told sometimes try to swallow small coins but this is foolish. The coin can be produced swiftly enough in such cases by emetics and laxatives. Dancer of Gor page 238
The books briefly mention a number of other drugs and medicines used on Gor. Laxatives and emetics exist. For a more natural purgative, the leaves of the brak bush can be chewed.
