Marianne Diez is a doctor of veterinary medicine who graduated from the University of Liège in Cureghem in 1989. After spending 2 years in companion animal practice, she joined the pet nutrition department of the university's veterinary medicine department de Liège in 1991 to do a PhD on the effects of dietary fiber in dogs (Contribution to the study of dietary fiber in dog's diet: effects on faeces characteristics, nutrient digestibility and blood metabolites, 1998). She thus began a scientific and academic career specializing in teaching, clinical and research on the nutrition of companion animals. She is also a founding member of the European College of Nutrition (ECVCN) and a board member for many years. She is the author of numerous original articles and lectures on obesity and its consequences in companion animals, prebiotics, the relationship between diet and disease, and the role of nutrition in preventive medicine.