When most people think about mental health, they think about therapy, medication, stress management, or perhaps childhood experiences. Rarely do they think about what’s on their plate.
But according to Dr. Andrea Cook, a UCSC professor, licensed clinical psychologist, and certified health coach, that may be changing.
Cook is part of a growing movement of researchers and clinicians exploring nutritional psychology, an emerging field that examines the two-way relationship between what we eat and how we feel. The science is still young, but the evidence is becoming increasingly difficult to ignore.
“We now have enough research to show that what you eat directly impacts mental health,” Cook says. “For years, the message was to eat healthy so you don’t develop heart disease or diabetes later in life. But now we’re seeing that nutrition can affect how you feel today.”
That distinction is particularly relevant for younger generations experiencing unprecedented rates of anxiety, depression, and stress.
“If you’re struggling emotionally, changing your nutrition may help you find relief now—not just decades from now,” she says.
A Missing Piece in Psychology
Cook’s interest in nutritional psychology grew out of her work as a health psychologist and her training in functional medicine health coaching. As she worked with clients managing chronic health conditions, she began noticing something that traditional psychology training rarely addressed.
“I was seeing dramatic effects from lifestyle changes,” she says. “It became clear that this was something missing from our clinical training and even from our basic understanding of psychology.”
Rather than viewing mental health solely through the lens of thoughts, emotions, and life experiences, nutritional psychology adds another dimension: the role of biology.
The field examines how food influences mood, cognition, energy levels, stress resilience, and emotional well-being. At the same time, it explores the reverse relationship, how emotions, stress, trauma, and mental health influence eating behavior. In other words, food affects mental health, and mental health affects food choices.
More Than Willpower
One of the most compelling aspects of nutritional psychology is its challenge to the idea that healthy eating is simply a matter of willpower. Most of us know what we should eat. The challenge is understanding why we don’t.
“It’s one thing to say, ‘I know I shouldn’t eat sugar,'” says Cook. “It’s another thing to understand why you keep reaching for it.”
That conversation can include everything from stress eating and family influences to the controversial topic of food addiction. While researchers continue to debate the term, Cook notes that certain highly processed foods are specifically engineered to stimulate reward pathways in the brain.
“We’re not saying all foods are addictive,” she says. “But some foods have been designed to activate the brain in ways that are similar to substances of abuse.”
Understanding those biological and psychological influences can help reduce shame and self-criticism around eating behaviors while opening the door to more effective solutions.
When Food Gets in the Way
Cook believes nutritional psychology can complement traditional psychotherapy rather than replace it. When clients come seeking help for anxiety, depression, or relationship challenges, she often begins with education.
“You may not know this,” she tells them, “but we’re finding that foods can directly affect how much energy you have, how much you worry, how fatigued you feel, and even how clearly you think.”
That doesn’t mean childhood experiences or emotional patterns stop mattering. Rather, nutrition can influence a person’s ability to address those deeper issues.
“Sometimes food is getting in the way of making changes,” she says. “It can affect whether you have the energy to take a walk, have a difficult conversation, or engage fully in therapy.”
Building physical resilience, she says, often helps build emotional resilience as well.
A Personal Discovery
Cook’s passion for the subject is also personal. Like many people who came of age during the low-fat era, she spent years trying to follow conventional dietary advice.
“I was disciplined and hardworking, but I was hungry all the time,” she recalls.
Everything changed after meeting with a nutritionist who encouraged her to eat more protein and healthy fats and to pay attention to her body’s hunger signals. The results were dramatic.
“I remember thinking, ‘I’m a different person,'” she says. “I felt calmer. I wasn’t hungry all the time. I didn’t know I could feel like this.”
That experience reinforced her belief that nutrition can profoundly influence mood, energy, and emotional stability.
Beyond Nutrients
One of the most refreshing aspects of Cook’s approach is her rejection of rigid food rules. She often draws on principles from intuitive eating, which encourages people to reconnect with their body’s signals and develop a healthier relationship with food.
Instead of labeling foods as “good” or “bad,” she encourages what she calls nonjudgmental curiosity.
“This isn’t about getting it right,” she says. “It’s about continuing to explore what works for your body.”
That perspective also includes acknowledging the social and emotional dimensions of eating. Sharing meals, cooking with others, enjoying favorite foods in moderation, and finding pleasure in eating all contribute to well-being.
“It’s important to understand the difference between food that nourishes your body and food that comforts your emotions,” Cook says. “Both have a place. The key is awareness.”
Teaching the Next Generation
Cook’s popular UCSC course on nutritional psychology regularly attracts around 180 students each quarter. She even wrote the textbook herself after discovering a lack of educational resources in the field. The response from students has been overwhelming.
“They often tell me it’s one of the most meaningful and life-changing classes they’ve taken,” she says.
Perhaps most surprising, every class session includes a five-minute meditation. For Cook, that practice reinforces a central lesson of nutritional psychology: mental health is about far more than food alone.
“This is a lifestyle,” she says. “It’s not just eating the right foods. It’s also learning how to calm your nervous system in an era of chronic stress.”
In many ways, that may be the field’s greatest contribution. Nutritional psychology reminds us that mental health isn’t just in our heads. It’s also in our kitchens, our grocery carts, our dinner tables, and the daily habits that shape how we feel.
And for a generation searching for practical ways to improve well-being, that may be welcome news indeed.
READ NEXT: Looking for simple ways to put nutritional psychology into practice? Explore local superfoods available at Santa Cruz County farmers’ markets, then read why America’s protein obsession may be missing the bigger picture: fiber, balance and eating for long-term health.
