Hetzel's parents were originally from South Australia but in London at the time while Kenneth worked at the University College Hospital.

He later applied to join the Royal Australian Air Force as a medical officer but was denied on grounds of being unfit due to a long bout of pulmonary tuberculosis in 1945.

In 1954, Hetzel and his family travelled to London where he undertook a Research Fellowship in the Department of Endocrinology and Metabolism at St Thomas' Hospital.

[5] Hetzel worked in remote areas of Papua New Guinea with the Public Health Department of the then Territory, and his research concluded that the endemic goitre and associated cretinism was attributable to an iodine deficient diet.

This was part of the stimulus for the creation of the Iodine Global Network, then called the International Council for Control of Iodine Deficiency Disorders (ICCIDD), which is funded by various government, non-government and community organisations including the United Nations, the Global Alliance for Improved Nutrition, UNICEF, the World Health Organization, and the World Bank.

"[7] In 2010, the ICCIDD established a Basil Hetzel International Award for Communications for individuals who contribute to promoting awareness of iodine nutrition.

In the 1960s, he led research in Papua New Guinea that identified the link between iodine deficiency and significant brain damage in unborn children.