To millions of Malaysians, rice is at the center of most meals. Many start and end their day with it. Rice is the basis of the national dish, nasi lemak, which translates to “fat rice.”

So when Prime Minister Najib Razak said this past week that he preferred quinoa because it was “better than rice,” he stirred up a tempest in a lunch bowl.

Mr. Najib is facing general elections under a cloud of a corruption accusations. He has denied wrongdoing in connection with a graft scandal centering on the 1Malaysia Development Berhad state fund.

Though he has been blamed for a higher cost of living since a goods and services tax began in 2015, Mr. Najib is widely expected to win a third term, thanks to a divided opposition, an upbeat economy, rural support and the redrawing of electoral boundaries that critics say favors the government.