Geraldine studied Medicine and Physical Anthropology at the University of Cambridge then spent time as a volunteer on a Maternal and Child health and nutrition project in Burkina Faso before completing her clinical training at the University of Birmingham. Inspired by a Masters programme in Human Nutrition at the London School of Hygiene and Tropical Medicine she went on to doctoral research on seasonality of adult energy nutrition in rural S India. Since 1986 she has been based in Aberdeen, first at the Rowett Research Institute where she set up a human volunteer facility for studies on obesity, then at the University Medical School where she coordinated the MSc Nutrition programmes from 1991-2000 and carried out research in dietary assessment and nutrition epidemiology. In this capacity she supervised over 20 PhD projects to completion, many involving students from and/or field work in Lower and Middle Income Countries. 

Geraldine was appointed to a personal chair in Public Health Nutrition at the University of Aberdeen in 2010 and became an Emeritus Professor in 2014. She has been a member of national and international grant panels and is currently Registrar for the Association for Nutrition, having been elected as a Fellow of the Association in 2015. She joined the Global Academy of Agriculture and Food Security in 2018.