autoalimentar

To self-feed or feed oneself, used both literally (a person or animal feeding itself) and, more often in modern usage, figuratively for a system or process that sustains itself: el círculo vicioso se autoalimenta.

• El bebé ya empieza a autoalimentarse con la cuchara. — The baby is already starting to feed himself with a spoon.
• El rumor se autoalimentaba con cada nueva versión de la historia. — The rumor kept feeding itself with every new version of the story.
• La máquina se autoalimenta de materia prima sin intervención humana. — The machine feeds itself raw material without human intervention.

Missing the figurative, far more common use — most native speakers reach for autoalimentarse to describe a self-perpetuating cycle (fear, conflict, a rumor), not literal eating.