One verse

Srimad Bhagavatam 4.23.5

4.23.5

कन्दमूलफलाहार: शुष्कपर्णाशन: क्‍वचित् । अब्भक्ष: कतिचित्पक्षान् वायुभक्षस्तत: परम् ॥ ५ ॥

kanda-mula-phalaharah suska-parnasanah kvacit ab-bhaksah katicit paksan vayu-bhaksas tatah param

kanda
trunk
mula
roots
phala
fruits
aharah
eating
suska
dry
parna
leaves
asanah
eating
kvacit
sometimes
ap-bhaksah
drinking water
katicit
for several
paksan
fortnights
vayu
the air
bhaksah
breathing
tatah param
thereafter.

In the tapo-vana, Maharaja Prthu sometimes ate the trunks and roots of trees, and sometimes he ate fruit and dried leaves, and for some weeks he drank only water. Finally he lived simply by breathing air.