There was an error in my calculations, which are based on freshman college physics I took in the 90s, so never mind.

Attempt #2: Gravitational potential energy = kinetic energy = .5massescape velocity^2. = .5human bodyweight kg 11,200 m/s. Convert the units and you've got a few years worth of calories (which I think I mixed up with kilocalories the first time).

Yes, I get a few year's worth of kilocalories (1 kcal = 4180 Joules, and assuming a 2,000 kcal per day diet) for a 100 kg human.