Dr. Samuel M. Weisberg, 76, a biochemist and retired food company official who was executive director of the League for International Food Education (LIFE) from 1968 to 1975, died Friday at Holy Cross Hospital after a heart attack. He was a resident of Silver Spring.

From 1931 to 1958, Dr. Weisberg worked for National Dairy Industries in Baltimore and New York state, then joined the Kraft Co. in Chicago, where he became research and development director before retiring in 1968.

Later that year he came to this area and became LIFE's executive director. That organization is a clearinghouse for nutritional information and advice to developing nations. In addition to serving as LIFE's executive director, he also edited the organization's newsletter and helped organize international conferences before retiring in 1975.

Dr. Weisberg was a native of Boston and a 1926 graduate of Tufts University. He earned a master's degree at American University, and in 1931 received a doctor's degree in biochemistry at Johns Hopkins University.

During the 1920s, he worked for a short time as a chemist with the Agriculture Department. His research included work on milk homogenization and the digestibility of various proteins. He also did work that helped lead to the manufacture of synthetic rubber in this country during World War II and to the production of burn ointments.

Dr. Weisberg was a member of the Washington Hebrew Congregation.

His first wife, of 45 years, the former Anne Wolpe, died in 1974. Dr. Weisberg's survivors include his wife, the former Lucille Bloch Rosen, of Silver Spring; three daughters by his first marriage, Betsy W. Buxer, of Phoenix, Myra W. Sklarew and Janice W. Eanet, of Bethesda; a stepson, Frederic L. Rosen, of New Haven, Conn.; a stepdaughter, Margaret R. Tucker, of Houston; seven grandchildren and two stepgrandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the Washington Hebrew Congregation.