High-symmetry lipid nanoparticles with internal bicontinuous cubic phase structure (cubosomes) are prepared from a simple emulsion containing a mixture of a nondigestible lipid (phytantriol) and a digestible short-chained triglyceride using enzymatic lipolysis of the incorporated short-chained triglyceride. The lipolytic products partition away from the nondigestible lipid, resulting in crystallization of the cubic-phase internal structure. Time-resolved small-angle X-ray scattering revealed the kinetics of the disorder-to-order transition, with cryo-transmission electron microscopy showing an absence of liposomes. The new approach offers a new "sideways" method for the generation of lipid-based nanostructured materials that avoids the problems of top-down and bottom-up approaches.