Eating Optional: To an extent. Early modifications, like the chloromorph/dryad clade, merely need to eat less due to their ability to gain energy through photosynthesis, but something close to the complete trope is possible. Just not terribly convenient, as by the time you’ve crammed an entire closed-ecology life-support module and a power supply for it inside a ‘shell, it’s a damned clunky body to have to walk around in – and since thermodynamics, and recycling isn’t perfect, you’ll still need to replenish some materials from time to time anyway.

All of which is to say: while it’s an interesting technical challenge to work on, and the spin-off have been useful, personal autarky is not, in practice, a terribly useful technology per se.