Meet Dr. Susan B. Roberts, PhD
Founder of iDiet | Renowned Nutrition Scientist | Global Authority on Behavior Change and Cognitive Nutrition Inteventions
Dr. Susan B. Roberts is one of the world’s most respected scientists in the fields of nutrition, obesity prevention, and behavior change. Over the course of her 30+ year career, she has transformed how we understand weight loss, hunger, food preference, and the role of nutrition in both early childhood development and aging brains. Her research spans five continents and addresses human health across the entire lifespan—from rescuing malnourished children to protecting aging adults from cognitive decline.
Dr. Roberts is the creator of iDiet: the only commercial weight-loss program grounded in decades of clinical trials, neuroscience, and behavioral science. Unlike fads or willpower-based plans, iDiet was built from the ground up to address the real, biological drivers of eating behavior—and to help people lose weight sustainably and happily.
Her academic leadership has shaped both U.S. and global public health strategies. In 2023, after decades at Tufts University, she joined the Geisel School of Medicine at Dartmouth as Senior Associate Dean for Foundational Research, where she now leads large-scale, interdisciplinary initiatives to advance human health through science-based innovation.
Career Highlights
Dr. Roberts earned both her BSc and PhD in Nutrition from the University of Cambridge in the UK. She completed postdoctoral work at the Massachusetts Institute of Technology (MIT) and research fellowships in pediatrics and metabolism before relocating to the U.S. in 1987.
At Tufts University, she served as:
- Senior Scientist at the USDA Human Nutrition Research Center on Aging
- Professor at the Friedman School of Nutrition Science & Policy
- Adjunct Professor of Psychiatry and Pediatrics at Tufts Medical School
- Co-Director of the Tufts Institute for Global Obesity Research
Over three decades, she led pioneering research in food behavior, energy metabolism, appetite regulation, and cognitive health, with continuous funding from the NIH and other top scientific agencies.
Today at Dartmouth, Dr. Roberts guides foundational science strategy across the medical school and directs complex research partnerships across fields like neurology, aging, public health, and weight regulation.
Science You Can Use
Dr. Roberts developed the iDiet program after years of clinical frustration watching patients fail on traditional diets—not because they lacked willpower, but because the diets didn’t align with how human hunger, reward, and habit systems actually work.
She asked: What if we could reprogram our brains to prefer healthier foods?What if we could feel full on fewer calories, without cravings?
iDiet is her answer. Backed by clinical trials and designed using principles from neuroscience, cognitive behavioral therapy (CBT), and nutrition science, iDiet works by:
- Training your brain to prefer healthier foods
- Restructuring environmental triggers that fuel overeating
- Using satisfying, hunger-suppressing meals based on volumetrics and food science
- Providing behavioral tools to disrupt habit loops and emotional eating
In multiple peer-reviewed trials, iDiet participants lost 8–12% of body weight, improved their metabolic health, and—most importantly—kept the weight off. fMRI studies showed measurable changes in brain activation, with reduced reward response to junk food and increased reward from healthy foods—proof that preferences were being neurologically reshaped.
Reversing Cognitive Delays in Malnourished Children
Dr. Roberts’ impact goes far beyond weight loss. She has led groundbreaking research in global child nutrition, showing that cognitive delays caused by early malnutrition can be reversed with the right nutritional tools.
In studies conducted in Guinea-Bissau, Gambia, Kenya, and India, her team designed and tested advanced nutritional supplements aimed not just at survival, but at restoring brain function in children already showing developmental impairment.
These interventions led to improvements in:
- Learning and memory
- Cognitive speed and attention
- Long-term educational outcomes
This research challenged the long-standing belief that early cognitive damage from malnutrition was permanent. By focusing on brain-targeted nutrient formulations, Dr. Roberts opened new possibilities for global health—bridging neuroscience and humanitarian work.
Preventing Dementia Through Nutrition
As rates of Alzheimer’s and dementia rise, Dr. Roberts has turned her expertise to a critical question: Can we protect aging brains through diet?
Her lab has conducted a series of intervention trials in older adults, testing specific combinations of nutrients and eating patterns designed to:
- Slow cognitive decline
- Reduce inflammation and oxidative stress
- Support memory, attention, and executive function
These trials have used advanced tools like functional MRI and near-infrared spectroscopy to observe brain activity in real time, allowing her team to track how targeted dietary interventions alter brain metabolism and function.
The findings are promising: with the right support, nutrition can become a frontline tool in the fight against age-related cognitive decline.
Leading the Fight Against Weight Regain
While most diets focus on losing weight, Dr. Roberts has zeroed in on what happens after—when the body fights to regain lost pounds.
She is the principal investigator of a major NIH-funded research consortium uniting seven leading U.S. institutions to study the physiology of weight regain. This project is decoding:
- How metabolism shifts after weight loss
- Why appetite hormones like ghrelin and leptin sabotage maintenance
- What psychological and behavioral strategies best support long-term success
This research is essential to solving the global obesity epidemic, and it directly informs iDiet’s advanced maintenance strategies.
Building the World’s Largest Weight Control Dataset
Dr. Roberts also co-founded the International Weight Control Registry (IWCR)—a global, NIH-supported project that collects real-world data on how people successfully lose weight and keep it off.
With participants in 19 countries, the IWCR aims to map the behaviors, environments, and psychological traits of those who defy the odds and maintain healthy weights long-term. It’s the largest project of its kind, and its insights are reshaping public health policy, app design, and clinical programs worldwide.
Watch Dr. Roberts discuss her mission – to solve the obesity epidemic and finally give the word “diet” a good name.
Recognition and Legacy
Dr. Roberts is the author of over 300 peer-reviewed scientific papers, including publications in the New England Journal of Medicine, JAMA, and BMJ. She has been continuously funded by the NIH and other top scientific agencies for more than three decades, and she ranks among the top 0.1% of biological scientists worldwide.
She has received numerous awards, including:
- The E.V. McCollum Award for lifetime achievement in nutrition science
- The W.O. Atwater Lectureship, one of the highest honors in public nutrition
- The Will Solimene Award for excellence in medical communication
- The General Mills Innovation Award for applied food science research
She is also a sought-after speaker and expert communicator, with appearances in TIME, The New York Times, The Washington Post, and national television outlets.
Science and Psychology
What truly distinguishes Dr. Roberts is not just her scientific brilliance—but her empathy. She understands that food is more than fuel. It’s emotion, culture, comfort, and habit. And she knows firsthand how painful the cycle of dieting and weight regain can be.
Through iDiet and her global research, she has created a new path—one that replaces guilt with science, shame with strategy, and hunger with hope.
Her work empowers individuals to take control of their health—not by fighting biology, but by working with it. With every study, every breakthrough, and every iDiet success story, Dr. Roberts is helping to rewrite the story of what’s possible for human health.
Major findings from Dr. Roberts’ lab includes:
- A study incorporating fMRI images of iDiet participants brains showing their responses to foods had been retrained to prefer healthier foods over sugary and fat-laden options (Nutrition & Diabetes (2014) 4, e129; doi:10.1038/nutd.2014.26)
- A study showing the iDiet program produces lower attrition, higher satisfaction and greater weight loss than other group weight loss programs, with clinically relevant beneficial effect on cardiometabolic risk factors (Am J Clin Nutr April 2013 vol. 97 no. 4 663-664)
- The first research providing solid evidence that dietary fiber is a major aid in weight control (Howarth et al. 2001; Gilhooly et al. 2008)
- The first research showing excess dietary variety linked to increased body fatness (McCrory et al 1999).
- The first compilation of research studies to demonstrate that exercise has only a small effect on weight loss, distinct from benefits for preventing weight regain (Elder et al. 2007).
- The first laboratory identifying core characteristics of craved foods and developing a plan for treatment based on associative conditioning (Gilhooly et al. 2007).
- The first research showing that restaurant calorie listings are inaccurate and that for foods lower in calories the listings understate food portions given to consumers (Urban et al 2009 and 2010).
- The first study identifying ‘disinhibition’ as a significant behavioral challenge in weight control (Hays et al 2002).