SB 3.33.28

tad-dehaḥ parataḥ poṣo
 ’py akṛśaś cādhy-asambhavāt
babhau malair avacchannaḥ
 sadhūma iva pāvakaḥ
Word for word: 
tat-dehaḥ — her body; parataḥ — by others (the damsels created by Kardama); poṣaḥ — maintained; api — although; akṛśaḥ — not thin; ca — and; ādhi — anxiety; asambhavāt — from not occurring; babhau — shone; malaiḥ — by dust; avacchannaḥ — covered; sa-dhūmaḥ — surrounded with smoke; iva — like; pāvakaḥ — a fire.
Translation: 
Her body was being taken care of by the spiritual damsels created by her husband, Kardama, and since she had no mental anxiety at that time, her body did not become thin. She appeared just like a fire surrounded by smoke.
Purport: 

Because she was always in trance in transcendental bliss, the thought of the Personality of Godhead was always carefully fixed in her mind. She did not become thin, for she was taken care of by the celestial maidservants created by her husband. It is said, according to the Āyurvedic medical science, that if one is free from anxieties he generally becomes fat. Devahūti, being situated in Kṛṣṇa consciousness, had no mental anxieties, and therefore her body did not become thin. It is customary in the renounced order of life that one should not take any service from a servant or maid, but Devahūti was being served by the celestial maidservants. This may appear to be against the spiritual concept of life, but just as fire is still beautiful even when surrounded by smoke, she looked completely pure although it seemed that she was living in a luxurious way.