Not me. The fruit flies got into my compost bucket full of nothing but banana peels and multiplied into about a million healthy vigorous flies. They turned the counter tops black. I made a trap baited with banana peels (a jar with a paper funnel) and released them outside.

Well first there is still alot of nutrition left in the banana peel and maybe in desperate times it would be worth exploring how to get something palatable out of them. Second, where do they get their protein? I googled: fruit flies nitrogen fixation - and found:

"Enterobacteria-mediated nitrogen fixation in natural populations of the fruit fly Ceratitis capitata.

Nitrogen, although abundant in the atmosphere, is paradoxically a limited resource for multicellular organisms. In the Animalia, biological nitrogen fixation has solely been demonstrated in termites. We found that all individuals of field-collected Mediterranean fruit flies (Ceratitis capitata) harbour large diazotrophic enterobacterial populations that express dinitrogen reductase in the gut. Moreover, nitrogen fixation was demonstrated in isolated guts and in live flies and may significantly contribute to the fly's nitrogen intake. The presence of similar bacterial consortia in additional insect orders suggests that nitrogen fixation occurs in vast pools of terrestrial insects. On such a large scale, this phenomenon may have a considerable impact on the nitrogen cycle."

[www.ncbi.nlm.nih.gov]

Maybe if one achieved absolute perfection it would be possible to harbor such nitrogen fixing bacteria within and thereby satisfy one's protein needs without the need for protein in the fruit one consumed.

I heard monkeys eat the banana peel if it is organic but not if it is commercial.

You can distill banana peels for ethanol. I know someone in costa rica with website make alcohol fuel with bananas