
The EMBRACE Study
This study looks at how weight loss surgery leads to changes in the diet and gut bacteria, and how these changes affect brain health. This includes memory, concentration and language!
GENERAL INFORMATION | ABOUT THE STUDY | WHY IS THE STUDY IMPORTANT? |
INTERESTED IN JOINING? | FREQUENTLY ASKED QUESTIONS | MEET THE TEAM! |
RELATED PUBLICATIONS | FUNDING & PARTNERS | CONTACT US |

General Information
What is metabolic bariatric surgery?
Metabolic bariatric surgery, commonly known as weight loss surgery, is a safe and effective treatment option for severe obesity.
It is a procedure that changes the shape and function of your stomach and the digestive system. This helps promote weight loss.
The two most commonly performed procedures are:
- Sleeve gastrectomy: a portion of the stomach is removed
- Roux-en-Y gastric bypass: a small pouch at the top of the stomach is created and is connected to the small intestine
Common benefits of metabolic bariatric surgery include
- Weight loss
- Improvements in chronic health conditions such as diabetes
- Improved quality of life
The surgery changes the way the body works, including what and how much a person can eat and the types of the bacteria in their gut.
Research shows that there is a connection between diet and gut bacteria, and that the number and kind of gut bacteria can impact the health of our brain and how it works. Our goal with this study is to better understand how this all works.

About the Study
We are recruiting adults above the age of 30 to participate in our study.
There are three groups for testing:
- Bariatric-surgery group: Individuals who are scheduled to undergo metabolic bariatric surgery.
- Waitlist group: Individuals who are on the waitlist for metabolic bariatric surgery. They are matched with the bariatric group based on age, sex, and body mass index (BMI).
- Control group: Healthy individuals who are matched with individuals in the bariatric-surgery group based on age and sex. People in this group will only be tested once.
Tests:
- Online Questionnaire: Sociodemographic and health behaviour questions
- Lab & Home Tests: Physiological assessments (body measurements, blood-, urine-, and fecal-based measures).
- Brain Testing: Neuropsychological cognitive tests, and structural MRI (magnetic resonance imaging).

Why is the Study Important?
This study will help us know more about how our gut bacteria and diet influence each other and affect brain health.
The main goal of this study is to examine the changes in the diet and the gut bacteria of people who had bariatric surgery during one year, and how these changes affect their brain health.
This study can help us:
- Know more about how our gut bacteria and diet influence each other and affect brain health
- Better understand how metabolic-bariatric surgery affects our hormones and how our body reacts to infections

Interested in joining?
Want to join our study and be part of this exciting project?
Are you a healthy adult over 30 years old?
If you are interested, please complete the submission form and one of our research assistants will reach back to you as soon as possible.
*Compensation provided

Frequently Asked Questions
What are you looking for when you take blood?
We are looking at your body chemistry. This includes:
- Signs of inflammation
- Hormone levels
- Levels of vitamins and nutrients
- Other measures that tell us about how the cells in your body function
Will I have access to the test results?
No, you will not have direct access, but if we notice anything unusual, with your permission, we will contact your physician.
What tests will I be doing at the lab and at home?
- Lab tests will be done at Montréal’s Hôpital Sacré-Coeur and will include:
- Blood test
- Weight
- Height
- Home tests will include
- Using a mobile app for 3 days to record the food you eat.
- Collecting your urine over a 24-hour period.
- Collecting one stool sample.
Home tests/tasks take approximately one hour to complete in total.
What do the brain function tests include?
Brain function tests will be done at the Institut universitaire de gériatrie de Montréal and will look at:
- Reading
- Use of language
- Attention, learning, memory and problem-solving
Brain function tests take approximately one hour to complete
What does the online questionnaire include?
The online questionnaire asks questions about your:
- Medical history
- Physical activity
- Mental health
- Lifestyle habits
- Diet
- Background information such as age, sex, and income
The online questionnaire takes 45 minutes to complete

Meet the Team
Principal Investigators:
Simon L. Bacon, PhD (physiologist), Professor, Department of Health, Kinesiology, and Applied Physiology, Concordia University, Co-Director Montreal, Behavioural Medicine Centre (MBMC), Centre intégré universitaire de santé et de services sociaux du Nord-de-l’Île-de-Montréal (CIUSSS) – Hôpital du Sacré-Coeur de Montréal (HSCM) Research Centre
Tair Ben Porat, PhD (nutritionist), Department of Health, Kinesiology, and Applied Physiology, Concordia University and CIUSSS du Nord-de-l’Île-de-Montréal – HSCM Research Centre
Co-Principal Investigator:
Kim Lavoie, PhD (psychologist), Department of Psychology, Université du Québec à Montréal and CIUSSS du Nord-de-l’Île-de-Montréal – HSCM Research Centre
Co-Investigators:
- Angela Alberga, PhD (physiologist), Department of Health, Kinesiology and Applied Physiology, Concordia University
- Marie-Claude Audet, PhD (neuroscientist), School of Nutrition Science, University of Ottawa
- Sylvie Belleville, PhD (neuropsychologist), Institut universitaire de gériatrie de Montréal (IUGM) research director and professor at Univeresité de Montréal
- Tamara Cohen, PhD (nutritionist), Director of Dietetics at UBC
- Dajana Vuckovic, PhD (biochemist), Department of Chemistry and Biochemistry, Concordia University
- Pierre Y. Garneau, MD (surgeon), Chief of general surgery service, CIUSSS du Nord-de-l’Île-de-Montréal – HSCM
- Patrick Marion (patient investigator)
- Radu Pescarus, MD (surgeon), CIUSSS du Nord-de-l’Île-de-Montréal – HSCM
- Elham Rahme, PhD (biostatistician)- Professor at McGill
- Sylvia Santosa, PhD (nutritionist), Research Centre, CIUSSS du Nord-de-l’Île-de-Montréal – HSCM and Department of Health, Kinesiology and Applied Physiology, Concordia University
- Anne-Sophie Studer, MD (surgeon), CIUSSS du Nord-de-l’Île-de-Montréal – HSCM
Students
- Kelly Acevado (D.Psy Candidate)
- Patricia Acosta (PhD Student), Human Nutrition, University of British Columbia
- Jessica Burdick (MSc Student), Department of Health, Kinesiology and Applied Physiology, Concordia University
- Reyhaneh Yousefi (PhD Candidate), Department of Health, Kinesiology and Applied Physiology, Concordia University
- Robbie Woods
Staff
- Tarek Allaw, Research Assistant
- Ioana Minoiu, Registered Nurse
- Richelot Gift Ayangma Mouko, Research Assistant
- Lidia Saidi, Research Assistant
More About the Project Team
Simon Bacon, PhD
Simon Bacon, PhD, FTOS, FCCS, FABMR, is the principal investigator of the Embrace project and Co-Director of the Montréal Behavioural Medicine Centre. He is a researcher at the Centre intégré universitaire de santé et service sociaux du Nord-de-l’Île-de-Montréal, and co-lead of the International Behavioural Trials Network (IBTN). He is a full professor in the Department of Health, Kinesiology, and Applied Physiology at Concordia University, the Canadian Institutes of Health Research (CIHR) Strategy for Patient-Oriented Research (SPOR) Chair in Innovative, Patient-Oriented, Behavioural Clinical Trials, and the FRQS co-Chair in Artificial Intelligence and Digital Health for Health Behaviour Change. Dr. Bacon’s Research is centered around the role of lifestyle factors, including health behaviours and psychological factors, in the development (primary and secondary prevention) and progression (tertiary prevention) of non-communicable chronic diseases (NCDs), and certain communicable diseases (e.g., COVID-19). Dr. Bacon has won research awards from the Canadian Hypertension Society, Canadian Institutes of Health Research, McGill University, National Institutes of Health (US), European Society of Hypertension, and International Society of Psychoneuroendocrinology.
Tair Ben Porat, PhD
Tair Ben Porat, PhD, graduated with Excellence A first degree in Nutritional science at the Agriculture Faculty of the Hebrew University, and obtained her PhD at the Department of nutrition and Metabolism of the Faculty of Medicine the Hebrew University, Jerusalem, Israel. She also holds a Master of Public Health (MPH), from the Sackler School of Medicine, Tel Aviv University. Her research focuses on nutritional and metabolic aspects pre- and post-bariatric surgery. During the last decade, Dr Ben Porat have managed the bariatric surgery nutritional therapy for patients with severe obesity at Hadassah Hebrew University Medical Center. She has previously initiated the establishment of a prospective medical database for bariatric patients in Hadassah Hebrew University Medical Center, and since then, she has been a main/co-investigator and collaborator on a considerable number of studies in fields of obesity and bariatric surgery. Dr Ben Porat currently serves as the Chair of the “Bariatric Surgery Forum” of the Israeli Dietetic Association, as a committee member of the Israeli Society for Metabolic and Bariatric Surgery, and as the Chair of the Integrated Health Committee the European chapter of the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO-EC). Through these, she has been able to translate her work into clinical guidelines and national position statements. In 2020 Dr Ben Porat has been awarded with the Hebrew University Excellent PhD Dissertation and the Hebrew University Scholarship Program for Post-Doctoral Excellent Female Students, as well as the FRQS scholarship (QC, Canada) for a 2-year postdoctoral fellowship. Due 2021 she has joined the Montreal Behavioral Medicine Center for her post-doctoral studies. Her focus is in exploring and understanding bariatric procedure’s impact on mental, nutritional and metabolic outcomes among target groups as well as elucidating the combination of genetic/microbiota factors and patient behavior/lifestyle as a key factor to establish innovative personalized future therapy.
Kim Lavoie, PhD
Kim Lavoie, PhD, FCPA, FABMR is is Co-Director of the Montréal Behavioural Medicine Centre, and a researcher at the Centre intégré universitaire de santé et service sociaux du Nord-de-l’Île-de-Montréal. She is a full professor in the Department of Psychology at the University of Quebec at Montreal (UQAM) and holds the Tier 1 Canada Research Chair in Behavioural Medicine. She holds several national and international leadership positions including Co-Lead of the International Behavioral Trials Network and Chair of the Canadian Network for Health Behavior Change. Dr. Lavoie’s work focuses on research in three areas: 1) the impact of psychological stress (e.g., depression, anxiety) and lifestyle factors (diet, exercise, smoking, medication adherence) on the development and progression of chronic illnesses (e.g., cardiovascular disease, asthma, COPD, and obesity); 2) psychophysiological and behavioral mechanisms linking psychological stress to disease; and 3) behavioural medicine (e.g., behavioral interventions for chronic illnesses, including motivational communication and cognitive-behavioral therapy). The goals of her research program include understanding how psychological and behavioural factors impact chronic disease development and progression, and using this data to develop, test and disseminate evidence-based behavioural interventions that target these factors. She is an internationally recognized expert in motivational communication; over 15,000 health professionals across Canada, the US, Europe, Australia and New Zealand have attended her professional training workshops. She currently holds multiple grants in the area of motivational communication training and efficacy for behaviour change in chronic disease.
Angela Alberga, PhD
Angela Alberga, PhD, is an Assistant Professor in the Department of Health, Kinesiology and Applied Physiology at Concordia University. Her interdisciplinary research program focuses on better understanding how societal, school and other broader institutional factors influence weight-related issues such as obesity, eating disorders, physical inactivity and weight stigma. Her MSc and PhD research focused on examining the effects of aerobic training, resistance training and combined aerobic and resistance training on the cardiometabolic health of adolescents with obesity. Her PhD work resulted in several high impact research articles in the field of medicine and obesity. To complement her expertise in clinical health research improving the physiological health of youth with obesity, her postdoctoral training focused on better understanding the psychological impacts of obesity. Her postdoctoral work also resulted in several high-impact publications including her co-authorship of the weight bias chapter of the new 2020 Canadian Adult Obesity Clinical Practice Guidelines published in the Canadian Medical Association Journal. Her graduate studies allowed her to collaborate with many multidisciplinary researchers (medicine, psychology, physiology, public health, etc.) to develop her skills in communication and knowledge transfer and improve her abilities as a sensitive communicator about body weight-related issues.
Marie-Claude Audet, PhD
Marie-Claude Audet, PhD, is an Associate Professor in Stress, Nutrition, and Mental Health in the School of Nutrition Sciences at the University of Ottawa. She also holds appointments in the Department of Cellular and Molecular Medicine at the University of Ottawa as well as at the Institute of Mental Health Research of the Royal Ottawa Mental Health Centre and the Department of Neuroscience at Carleton University. Dr. Audet’s current research program aims to understand how stressful experiences across the lifespan may come to alter the gut microbiota-immune-brain axis and promote vulnerability to mental illnesses, particularly depressive and anxiety disorders. A central component of her research involves the development of lifestyle approaches, including dietary and microbiota-targeted interventions and changes in physical activity, to prevent and/or attenuate symptoms of mental illnesses through the modulation of this axis. As the prevalence of depression and anxiety disorders in women is about twice as that of men, all her work is conducted in females and males, to allow the establishment of sex differences in relation to the microbiota, inflammatory and behavioral effects of stressors and of lifestyle interventions. Her research is currently funded by grants from the Natural Sciences and Engineering Research Council of Canada, the Social Sciences and Humanities Research Council (New Frontiers in Research Fund –Exploration), the Weston Family Foundation, as well as several internal awards.
Sylvie Belleville, PhD
Sylvie Belleville, PhD, is a full professor at the Psychology Department of University of Montreal and researcher at the Research Center of the Institut Universitaire de Gériatrie de Montréal. She is recognized for her work in the area of cognitive training for older adults and persons at risk of dementia and on the prevention of age-related cognitive decline. She identified processes of compensation and plasticity in mild cognitive impairment using brain imaging techniques. She also developed an important research program on the neuropsychology of memory in aging and dementia and has contributed to a better understanding of the neuropsychological deficits found in persons with very early signs of Alzheimer’s disease or mild cognitive impairment. She published 242 peer-reviewed articles. She currently holds a Tier 1 Canada Research Chair on the Cognitive Neuroscience of Aging and Brain Plasticity. She leads the Québec Consortium Québécois for early identification of Alzheimer’s disease (CIMA-Q) and the national team “Cognitive Intervention, Cognitive Reserve and Brain Plasticity” and “Brain Health Support Program” for the Canadian Consortium on Neurodegeneration in Aging. She received many prizes in recognition of her work, including the Adrien Pinard Prize of the Quebec Psychology Research Society, Professional Prize of the Quebec Psychologist Association and Doctorat Honoris causa from Mons University, Belgium. She is also a member of the prestigious Canadian Academy of Health Sciences.
Tamara Cohen, PhD
Tamara Cohen, PhD, is a registered dietitian, the Program Director of Dietetics and an Assistant Professor in the Faculty of Land and Food Systems at the University of British Columbia (UBC) (Food, Nutrition and Health | Human Nutrition). She is also an Investigator at the BC Children’s Hospital Research Institute. Dr. Cohen received her PhD in Nutritional Sciences from the School of Nutrition (McGill University, Montreal, QC). Her current research program focuses on eating behaviours throughout the lifespan, with the goal of improving dietary habits. To do so, her team bases their research on theoretical frameworks and applies them to the nutrition / dietary context. Her team is also involved in creating nutrition education tools, including creating a smartphone dietary self-monitoring application, with the goal of educating people about healthy eating and then assessing the tool’s impact on dietary change. Dr. Cohen holds a Scientist in Nutrition and Lifestyle award (2018-2023) with Concordia University through the R. Howard Webster Foundation (PERFORM Centre).
Dajana Vuckovic, PhD
Dajana Vuckovic, PhD, is an Associate Professor and Concordia University Research Chair (Tier 2) in the Department of Chemistry and Biochemistry and the Director of the Centre for Biological Applications of Mass Spectrometry at Concordia University. Dajana completed an Honorary BSc in chemistry from the University of Toronto, a PhD in analytical chemistry focusing on in vivo metabolomics at the University of Waterloo, and postdoctoral studies in chemical and quantitative proteomics at the University of Toronto. Beyond her research in clinical metabolomics and lipidomics which focuses on the development of novel methods to measure unstable and low abundance metabolites, Dajana is an active member of the Metabolomics QA & QC Consortium (mQACC) which aims to develop and disseminate new community-based guidelines to ensure high quality of untargeted metabolomics studies.
Pierre Y. Garneau, MD
Dr. Pierre Y. Garneau completed his medical and surgical training at Laval University. After a year of subspecialization at the University of Montreal, he began his career at the Hôpital du Sacré-Coeur in 1997 and performed the first bariatric procedure there. He then gradually devoted his career to bariatric, laparoscopic and robotic surgery. He is currently the director of the university training program in bariatric surgery at the University of Montreal. He is the Head of the Department of Surgery at CIUSSS-NIM and is also the Secretary of the Canadian Association of Bariatric Physicians and Surgeons (CABPS). His main research interests are focused on revision surgery.
Patrick Marion, BBA
Patrick Marion is an entrepreneur and a businessman. He has a Bachelor’s degree in Business Administration from the Université du Québec à Montréal. Patrick underwent bariatric surgery in August 2016. His engagement as an executive member of the Patient-Researcher Committee at the CIUSSS du Nord-de-l’Île-de-Montréal – Hôpital du Sacré-Cœur de Montréal has been a natural fit. Patrick is eager to improve the experience and quality of care for people living with obesity and those undergoing bariatric surgery.
Radu Pescarus, MD
Dr. Radu Pescarus completed his five-year residency in General Surgery at the University of Montreal. He then continued his subspecialty in Canada with a one-year fellowship in Bariatric and Minimally Invasive Surgery at McMaster University. Subsequently, he underwent a second fellowship in Portland, USA to further his knowledge in oesophageal gastric surgery as well as in the new field of gastrointestinal therapeutic endoscopy. He takes part in the surgery department of the Hôpital du Sacré-Coeur de Montréal and is currently an Associate Professor at the University of Montreal. His three areas of expertise are minimally invasive bariatric surgery, diaphragmatic and gastric surgery, as well as gastrointestinal therapeutic endoscopy. Dr. Pescarus is currently the Co-chair of Research in the General Surgery Program at the University of Montreal and as such is involved in research development throughout the residency program. His personal research interests include clinical and evaluative research in revisional bariatric surgery and the endoscopic treatment of upper gastrointestinal surgical complications.
Elham Rahme, PhD
Elham Rahme, PhD, is an associated professor at the Division of Clinical Epidemiology of the Department of Medicine at McGill University. She has over 25 years of experience in epidemiology, pharmacoepidemiology and biostatistics research. Amongst all the articles she has published and abstracts she has presented at national and international meetings, she has used the Quebec health administrative databases and survey data to conduct large population-based studies in several areas of research including mental health, autoimmune diseases, and cardio-metabolic diseases. Using these data, she has quantified the dual relationship between depression and diabetes and demonstrated, among other things, a higher risk of diabetes in individuals with severe (versus mild) psoriasis and a higher risk of depression in young adults with diabetes.
Sylvia Santosa, PhD
Sylvia Santosa, PhD, RD (CDO) is an Associate Professor in the department of Health, Kinesiology, and Applied Physiology at Concordia University, and a Canada Research Chair, Tier 2 in Clinical Nutrition. She earned her PhD in Nutritional Sciences from McGill University and is a registered dietitian in the College of Dietitians of Ontario. Her multidisciplinary lab, the Metabolism, Obesity, and Nutrition (MON) Lab at the PERFORM Centre, combines unique biological, physiological and nutritional techniques to investigate and understand the underlying effects of obesity that contribute to weight gain and disease. Her research has two main streams: the clinical stream investigates the nutritional needs of bariatric surgery patients, and the metabolic stream examines factors affecting regional fat tissue characteristics and how these characteristics, in turn, contribute to disease risk. The main goals of her research are to determine what makes obesity pathology different between individuals and how these differences can be accounted for in designing the better treatments for obesity.
Anne-Sophie Studer, MD
Dr Anne-Sophie Studer completed her medical degree in France through the University of Aix-Marseille. During her surgical training in general and digestive surgery, she also completed a master’s degree in biological anthropology. Upon completion of resident training, Dr Studer undertook multiple fellowships in both France and Canada, in minimally invasive surgery, bariatric surgery and trauma/acute care. Dr Studer is currently a practicing attending surgeon at Hospital Du Sacre-Coeur, Montreal, a tertiary teaching hospital affiliated with the University of Montreal. She has a special interest in revisional bariatric surgery and performs complex revisions with both laparoscopic and robotic platforms. Dr Studer also participates in the on call general surgical roster, performing emergency general surgery and trauma procedures.

Related Publications
Understanding the impact of radical changes in diet and the gut microbiota on brain function and structure: rationale and design for the EMBRACE study – View the publication
Refererence: Ben-Porat T, Alberga A, Audet MC, Belleville S, Cohen TR, Garneau PY, Lavoie KL, Marion P, Mellah S, Pescarus R, Rahme E, Santosa S, Studer AS, Vuckovic D, Woods R, Yousefi R, Bacon SL; EMBRACE Study Team. Understanding the impact of radical changes in diet and the gut microbiota on brain function and structure: rationale and design of the EMBRACE study. Surg Obes Relat Dis. 2023 Sep;19(9):1000-1012. doi: 10.1016/j.soard.2023.02.022. Epub 2023 Mar 17. PMID: 37088645.

Funding & Partners
The EMBRACE Project is funded by the Weston Family Foundation through its Microbiome Initiative. The Weston Family Foundation invests in innovation and learning to deliver measurable impacts to the well-being of Canadians.
Institutional Partners
This Montreal Behavioural Medicine Centre (MBMC) project is led in partnership with the Centre intégré universitaire de santé et de services sociaux du Nord-de-l’Île-de-Montréal (CIUSSS-NIM), Concordia University, the University of Ottawa, and the Institut universitaire de gériatrie de Montréal (IUGM).

Contact Us
- By phone: 514-338-2222 ext. 3944
- By email: embrace.cntml@ssss.gouv.qc.ca
We are located at: 5400, boul. Gouin O, Montréal, QC H4J 1C5, Canada