Question: if it really takes "10 kilocalories of energy for every calorie of food we produce", does it really make a lot of sense to generate electricity using bike power?

How to Feed the World While the Earth Cooks | Observations, Scientific American Blog Network

A conference on feeding the world must also feed itself. Having attended more than my share of such conferences, I can say that the norm is keynotes that rally the troops in favor of organics while said troops munch on tortilla or potato chips...As it stands, modern farming relies on a stable climate, endless supplies of fertilizers and water as well as being “enormously dependent on energy,” Kirschenmann noted at the conference. “It takes 10 kilocalories of energy for every calorie of food we produce. It’s the least efficient system we’ve ever had.”

Flashback:  Occupy Wall Street moves to bike power | Grist

Occupy Wall Street is switching to a greener option: human power. Generator bikes can provide 100 hours of power per six hours of pedaling, which helps fuel OWS needs like heat, light, phones, and laptops.