1. Teach the controversy!
2. The pyramids have settled substantially, even since 1676. It is perfectly feasible that they were largely hollow when originally constructed.
3. Perhaps they did hold food reserves, just in a more concentrated form than grain.
Helen Altman doin it rongAs any fule know, the pre-dynastic Egyptians were inspired to invent granaries by watching their alien scientist visitors pour millet seeds into skulls, and pour them out again, as a measure of cranial capacity.