In the 1930s it was Otto Warburg who won two Nobel Prizes for his discovery that cancer cells convert from using oxygen to sugar for energy.[4] There is always some “sugar burning” going on, but cancer cells generate up to 60% of their energy from sugar rather than ~5% in healthy cells.

By the way, because cancer cells utilize sugar for energy they expel lactic acid, and that is how the alkaline theory of cancer got started in the wrong direction. The acid is expelled outside of the cancer cell.

Indeed, the very way cancer is detected in this modern era is to image tumors using PET scan technology where radioactive sugar is instilled and the sugar is immediately attracted to feed the fast-growing ball of cancer cells wherever they may be, and then visualized on the PET scan.[5] The cancer industry certainly knows sugar feeds cancer.