With the new year comes another period of reflection on health, with many seeking to become more active or reevaluate their nutrition. But one William & Mary professor is hoping to push the boundary of how many approach wellness in their daily lives.
Stephanie Caligiuri, assistant professor of nutrition in kinesiology and director of the Neurobehavioral Nutrition Lab at William & Mary, is leading four studies that seek to strengthen the connection between neurobiology and nutrition.
Caligiuri’s longest study, beginning in May 2024 and lasting until 2027, focuses on intermittent fasting and will include around 300 people, making it one of the largest university-led fasting studies ever conducted and the biggest in William & Mary’s history. Caligiuri’s study aims to discover the different responses each subject will have to fasting. It will focus on how a fast can impact brain activity, cognition, stress, sleep, blood pressure, metabolism and more.
“In the past, studies had very small populations and very homogeneous types of populations where they were only recruiting people 18 to 25 with no diagnoses,” she said. “(With my) research, we can’t keep doing it this way. People respond differently to health interventions. To reflect that diversity, I need a big population.”
Challenging extrapolation
Caligiuri was inspired to begin analyzing fasting after she saw several young women entering her clinic presenting with insomnia, anxiety, high levels of stress and other severe symptoms. She found that most often, this was due to the patients attempting fasting to an extreme degree.
“This is a perfect example of why doing clinical research in a specific subgroup is dangerous,” Caligiuri said. “Majority of studies (previously on fasting) have been done in older men, and then it’s extrapolated to everyone.”
Knowing this discrepancy, Caligiuri took it upon herself to find a more representative sample that could model a safer, more effective way of fasting.
The study takes place over a period of four days, with a 24-hour fast beginning on the second day.
In all of these studies, Caligiuri uses a neuroimaging device, called Functional Near Infrared Spectroscopy (fNIRS), to accurately measure blood flow to the brain. There are only 15 of these devices in the United States, with two owned by the W&M Neurobehavioral Nutrition Lab.
Using near-infrared light, the device detects blood flow within the brain to detect changes in inhibition or activation. Responses to neutral images, food images, complex cognitive tasks as well as eating habits before, during and after fasting are tracked by the fNIRS device.
Blood collection through a lancet device analyzes plasma metabolomics with the help of liquid chromatography mass spectrometry. This allows Caligiuri to observe the circulating level of carbohydrates, amino acids, fatty acids and energy metabolites and compare them based on when the study participants recently ate, currently fasted or were recovering from a fasting period.
The study also has a standardized questionnaire to assess participants’ levels of fatigue, stress and energy throughout each period of the study. Additionally, blood pressure, waist circumference and body weight are tracked to assess how clinical parameters change over the three days of tracking.
Caligiuri’s studies aren’t limited to specific demographics like other studies – rather, the diversity in subjects helps paint a broader picture. For the fasting study alone, she’s had participants as young as 18 and as old as 78.
The inclusion criteria for the study are also broader than usual – only pregnant and breastfeeding women, along with people diagnosed as underweight or unable to fast by a physician are excluded for safety reasons. Other studies may also factor in certain diseases or conditions, but with Caligiuri’s parameters, as long as volunteers are 18 years old, they’re more than likely to be included.
“I don’t want to exclude people based on age or diagnoses,” she said. “I will record that. That can be an important parameter to consider for subgroup analysis.”
Inhibition versus activation
The lab’s other studies each cover different functions of the body-mind connection. A dance study has participants wear the fNIRS brain imaging device while creating specific choreography with no music to better understand “creative flow” and how to promote resilience in dancers.
A meditation study tracks brain activity while meditating, breath, heart rate, hunger and fullness to understand the relationship between meditating, interoception and eating behavior.
A basketball study tracks participants’ brain activity to predict reaction time and success levels to further promote athletic success and resilience.
fNIRS devices look at the prefrontal cortex, and depending on participant reaction, display an array of colors that Caligiuri will extract data from. If the prefrontal cortex shows shades of light blue or dark blue, it means the participant’s brain is showing inhibition and reduced blood flow; the darker the blue, the more inhibition accruing. If more yellow, orange or red is shown, the brain sees increased blood flow and is therefore more active in receiving information in the study.
Caligiuri tested the fNIRS herself when piloting the dance study with Professor of Dance Joan Gavaler. Gavaler has a professional background in dance, while Caligiuri dances in her free time. When conducting the test for the first time wearing the fNIRS, Gavaler’s neuroimaging showed her brain as a dark shade of blue, showing complete inhibition; Caligiuri was deep red.
“How we can interpret that is she was in a flow state and did not need to use the front part of her brain, which is more involved in critical thinking and decision making,” Caligiuri said. “It’s so habitual for her now, she’s been dancing for decades. Whereas (for) me, I’ve never done a choreographic task in silence before.”
Covering such a variety of demographics for these studies does not come without challenges. While Caligiuri has recruited both young college students and older Williamsburg residents, she’s hoping to find more middle-aged participants to better enhance her studies. People interested in joining one of the ongoing studies can visit the Neurobehavioral Nutrition Lab’s website at caligiurilab.pages.wm.edu.
The dance study, which was sponsored by the provost’s office through an interdisciplinary grant, is projected to end in September 2025. The athletic study, which due to its exploratory nature does not require as much in-depth analysis, will be submitted by June 2025. The meditation study is expected to be finished in January 2026.
Caligiuri has previously done 12 preclinical studies and nine clinical studies. Originally from Canada, she became fascinated with health and nutrition after discovering the Canada Food Guide, similar to the U.S. Food Pyramid, in the fourth grade, and realizing she had autonomy over her health and food choices.
“I just loved the idea of nutrition,” she said.
As a result, she attended university to become a dietitian, later deciding to pursue research. After working in New York for seven years, she sought to expand her work elsewhere, leading her to William & Mary.
Caligiuri is excited to continue her studies and cater to a diverse group of bodies and ages to promote more representation in science and autonomy over health and wellness.
“Everybody is different,” Caligiuri said. “That’s even more reason why we need to do more and larger clinical trials.”
William Oster, Communications Specialist