President of the Federation of European Nutrition Societies (FENS) and the International Forum of Immunonutrition for Education Research (i-FINER).

Honorary Professor of the University of Buenos Aires (Head of Nutrition at the Department of Health, Nutritition, Bromatology and Toxicology of the Faculty of Pharmacy and Biochemistry).

She has occupied many positions on the Board of Directors of the Spanish Society for Nutrition: Secretary (1997-1999), Board Member (1999-2001), Vice President (2001-2003), President (2003-2007), Vice President (2007-2010), Treasury (2010-2015). She has also been the Academic Correspondent of the Reial Acadèmia de Farmàcia de Catalunya since November 2011.

With a PhD in Pharmacy from the Complutense University of Madrid, her doctoral thesis was on the Joint Institute of Nutrition and Bromatology (UCM-CSIC) of the Faculty of Pharmacy, of which she was the Head from 1998-2002.

Director of the Immunonutrition Group of the Department of Metabolism and Nutrition of the Institute of Food Science and Technology of the Spanish Council for Scientific Research (CSIC).

Her scientific activity, dedicated to the study and applicability of immunonutrition, has involved research into the lifestyles of adolescents; within this, she has coordinated several multicentre and interdisciplinary projects related to nutrition, eating disorders and obesity with the aim of studying interactions and connections between different parameters relating to diet, eating behaviour, physical activity Another line of research has been the study of the immunomodulatory properties of nutrients, bioactive compounds, functional foods and nutraceuticals.

Marcos Sánchez has conducted 40 research projects (head researcher in 25 of them). She has been involved in 430 publications: 185 SCI articles, 29 SCI revisions. Editing of 13 supplements in international journals (SCI): American Journal of Clinical Nutrition (1997), European Journal of Clinical Nutrition (August 2002; December 2002), Nutrition (2003), Hospital Nutrition (2003) International Journal of Obesity (2004), British Journal of Nutrition (2007), Proceedings of the Nutrition Society (2008, 2010, 2011, 2012), Proceedings of the Annals of Nutrition and Metabolism (FENS-2013), Hospital Nutrition (2013), of which 7 supplements were dedicated to Immunonutrition, 3 to Nutrition, 1 to Obesity and 2 to Probiotics, in addition to 82 articles and 7 revisions in non-SCI journals. Books: 99 chapters, 8 books and 8 editions.

For many years she has been working in collaboration with other research groups, both nationally and internationally.

The most significant prizes she has been awarded in her scientific career have been: Contribution to the Study of Nutrition and Immunology, awarded by the Nutritional Immunology International Group. NAOS Strategy Prize for the Best Applied Research Project 2009: EVASYON study (coordinated by A. Marcos). Spanish Agency for Food Safety and Nutrition. Ministry of Health and Consumer Affairs. Recognition from Madrid City Council for her work as President of the Federation of European Nutrition Societies.