Mary Elizabeth Baugh: Redefining taste beyond the tongue

The following story was written in Fall 2025 by Michael Naval in ​ENGL ​4824​: Science Writing ​as part of a collaboration between the English department and the Center for Communicating Science.

When you think of flavor, you imagine your tongue: the sweet delicacy of chocolate or the sour taste of lemons. But for Mary Elizabeth Baugh, a nutritional neuroscience researcher at Virginia Tech, the definition of taste is more than what happens on the tongue. 

    In her research, Baugh has found that people’s food preferences aren’t driven by what something tastes like. Instead, much of the learning happens after we swallow: when the gut sends chemical signals to the brain. Baugh, a research scientist in the DONNUT Lab at the Fralin Biomedical Research Institute under Alexandra DiFeliceantonio, studies how these post-ingestive signals, and not just dieting habits or choice, shape what people learn to like over time.

    “Actually, most of flavor comes from olfactory sensations,” she explains. This changed her research toward post-ingestive signals, or the chemical messages between the gut and the brain that guide what we learn to like.

    Baugh's path began in high school, when the rise of the obesity epidemic caught her attention. She studied in the Department of Human Nutrition, Foods, and Exercise at Virginia Tech, became a registered dietitian, and spent a couple of years helping patients manage weight. From her experiences, she realized a pattern: People could lose pounds but rarely keep them off. 

    "People typically lose weight, but most people gain it back within about two years,” she recalls. This realization led her back to research, where she began asking a deeper question: Why do we eat what we eat and what drives our long-term food choices?

    In everyday language, the word "taste" is simple, and it ranges from flavor to texture to spice. Scientifically, taste looks at a few sensations, such as sweet, sour, salty, bitter, and umami. 

    "Taste and flavor are different," Baugh explains. "Flavor includes smell, texture, temperature, and the feedback you get from the gut after eating." 

    Gut feedback is the frontier of the DONNUT lab’s research. Baugh and her colleagues design beverages that look and taste equally sweet but differ in calories. By comparing how volunteers' bodies and brains respond, the researchers can see any post-ingestive signals that shape food preferences (Kelly et al., 2024). 

    Baugh's goal is to show that humans learn food preferences not just through conscious choice, but through biology.

    “[When] we consume sugar, it’s sensed in our gut, and that signal is relayed to the brain where it interacts with reward-related regions and can stimulate dopamine signaling,” Baugh explains.

   In an interview last year, Baugh described her most recent experiment where she and her colleagues gave participants drinks flavored with different flavors like acerola and bilberry (Kelley, 2025).

    “We try to use flavors that people don’t really have any preconceived notions or experiences with so that this learning can occur,” she says. Some of the drinks had real sugar, and the others had a non-caloric sweetener, but both tasted equally sweet. 

    Over multiple trials, participants preferred the calorie-containing drinks even though they couldn’t tell the difference by taste. The results showed that people with better blood sugar control (measured by hemoglobin A1c) learned these preferences more strongly; body weight measures like BMI didn’t predict anything. 

    “People with better glycemic control seemed to learn those flavor nutrient pairings faster. So it's not just taste” Baugh explains. “There's something internal, a signal from the body that reinforces learning.”

    Studying eating behavior in humans is much harder than studying it in animals. Humans have different variables that must be considered by researchers, such as food preferences, cultural upbringing, and preconceived expectations about visual cues. 

    “If we made a drink purple, most people would assume it was grape even if it didn’t taste like grape,” Baugh says. To avoid giving any subconscious cues, the research team now experiments with neutral symbols instead of using colors.

    Another challenge is measuring subtle metabolic responses. In a PLOS ONE article published in 2024, Baugh and her colleagues used a whole-room indirect calorimeter to track how the body responds to flavored drinks that had different sugars but identical calorie amounts. The study focuses on metabolic changes on how the body can process these small calorie loads rather than brain activity or flavor preferences.

    Baugh’s research has changed how we think about food and nutrition. Over many years, public health messages have focused on moderation and self-control. She argues that if our bodies need energy, changing this behavior means that we should change our environment. 

    “We should really be thinking not so much about changing ourselves, but changing [our] environment,” Baugh says. 

    Her research shows that our bodies respond differently to calories than to non-caloric sweeteners, but scientists don’t know exactly what these differences mean for long-term eating behaviors. Instead of concluding that sugar substitutes are harmful, Baugh explains that the key question is how the body recognizes nutrients after we consume them and how internal signals could influence what we learn to prefer over time. Understanding these mechanisms, she explains, is important before drawing conclusions about how sweeteners affect appetite or satisfaction.

    Furthermore, the research shows that improving diet will take more than just dieting and will power, and people should focus more on designing a food environment that works with how our biology learns and reacts to energy. 

    “It’s not removing pleasure,” Baugh expands. “It’s understanding how our bodies respond so that we can make choices that feel good and support long-term health.” 

    Ultimately, her work is not about inventing new foods but about understanding how our food environment interacts with our brains and bodies. Her research uncovers the biological mechanisms that affect our long-term eating behaviors, work that can help inform food policies and environments that better support public health.

    Baugh believes the most important question is understanding how our food environment works with different bodies and metabolisms. Her recent findings show that people vary widely in how they learn flavor-nutrient connections, even when their clinical measures appear to be normal. She hopes that future work will uncover why these differences exist. Baugh hopes her work will also shape public health decisions that focus on creating environments that better support healthy eating patterns, rather than on changing individuals. 

    “Of course, I still eat ice cream,” Baugh says with a smile. “Food should be enjoyable. The question is, ‘How much is too much?’”