Rasmus Larssen Alsaker (1883 – June 14, 1960) was a Norwegian American physician and alternative health writer.

[2] He received his licenses to practice medicine in Illinois and Colorado (1910) and in Missouri (1915).

[1] He was Health Director at the Sun-Diet Health Foundation in East Aurora, New York; he was William Howard Hay's successor in the position.

[2] Alsaker believed that his dietary method could cure practically all diseases.

Medical experts warned that Alsaker was misleading the public to self-diagnose and self-treat diseases of the heart.