Marie Reid studied psychology at the University of Glasgow then got her PhD there (1995) in Behavioural Sciences in the Faculty of Medicine, on the effects of carbohydrates on appetite and mood. This line of research has continued ever since, with funding from the Nuffield Foundation, the Biotechnology and Biosciences Research Council, the Department of Health and Industry. She also researches how people with eating disorders view themselves and the services that try to help them, often using qualitative or mixed methods.

She is a chartered Clinical and Health Psychologist, currently with an Honorary appointment at Edenhall Hospital, NHS Lothian. Previously she was an Honorary Clinical Psychologist in the Feeding and Eating Disorder Service of Great Ormond Street Hospital, London. Before arriving at Queen Margaret in 2005, she held a number of academic posts including Lecturer in Health Psychology, Department of Psychiatry University of Sheffield, Director of Communication Skills Teaching in Medicine at University of Leeds and Reader in the Department of Health and Human Sciences, University of Essex.

She is currently Chair of University Research Ethics Committee and Director of Doctorate in Health Psychology Programme.