Marsh was born in Berrien Center, Michigan.[1] She obtained a B.S. in 1929 and a M.S. with a major in foods and nutrition from University of Nebraska in 1938.[2] She worked as a dietitian at the Hinsdale Sanitarium (1929–1936) and was a research assistant at the University of Nebraska (1939–1944) under Ruth Leverton.[2][3] Marsh was a professor of Home Economics at Union College (1947–1950). She authored the column "Nutrition in the News" for the Seventh-day Adventist magazine Life and Health (1944–1950).[2]
Marsh was responsible for "Operation Nutrinaut" which was a study of the metabolic response of adolescent girls on a lacto-ovo vegetarian diet.[3] It was conducted with Dwain L. Ford chair of the Chemistry Department. The project that started in 1963 was split into several phases that involved the study of sixteen young women on a "rigorously controlled diet" for 25 days. During the experiment, the subjects lived together on the third floor of the Life Sciences Building and their bodily excretions and blood samples were chemically analysed.[3] More than 20,000 samples were collected over several years. Marsh, Ford and chief research assistant Dorothy K. Christensen published the results in the Journal of the American Dietetic Association in 1967. To date, the study is the largest collaborative research project that has been conducted at Andrews University.[3]
Marsh retired in 1976. She was listed as a professor in the Home Economics Department at Andrews University until 1984.[1]
Marsh was known for her research on bone health and vegetarianism.[1] In 1958, Marsh commented that lacto-ovo-vegetarian "is one of the world's very best diets".[4]
Marsh attended Loma Linda University's First International Congress on Vegetarian Nutrition in 1987.[5] She was one of seven reviewers for the 1988 position of the American Dietetic Association on vegetarian diets.[6]
^Havala, Suzanne; Dwyer, Johanna (1988). "Position of the American Dietetic Association: vegetarian diets--technical support paper". Journal of the American Dietetic Association. 88 (3): 352–355. doi:10.1016/S0002-8223(21)01980-5. PMID3346498. S2CID44567892.{{cite journal}}: CS1 maint: multiple names: authors list (link)