My life changed when I transitioned from high school to university. Finally, I could drive to school, make new friends, and bring food into my lectures without professors giving me the stink eye. There was one thing I didn’t anticipate at the end of my first year: the extra 25 pounds around my waist.
My friends and family told me I looked like melted vanilla ice cream––and I wasn’t alone. As I scrolled through Instagram, I noticed that my high school peers had also put on some weight. This made me feel a bit better about myself, but it also made me curious. Why did we all gain weight?
University students have a lot of responsibilities: meet deadlines, study for exams, attend lectures, balance health and maintain a social life. This brings a lot of stress for the majority of students (Balls, 2018).
Stress propels our bodies to enter the “flight-or-flight” mode. Hormones, such as cortisol, release into our bodies. Cortisol regulates mood, motivation, fear, and metabolism. When cortisol levels are high, we get more headaches, have trouble sleeping, and gain weight. But why?
Researchers at the University of Minnesota may hold the answer to that question. In 2015, they published a study in Frontiers in Nutrition that determined how stress impacts appetite and obesity in mice. Researchers exposed adult mice to a model of chronic subordination stress (CSS). They individually housed the mice for one week before introducing another mouse in the cage. The mice interacted for 10 minutes before they fought. After the fight, researchers placed a wire mesh in the cage that allowed continuous sensory contact between the winner and the loser. The loser was stressed; the winner wasn’t. Researchers fed both mice the same high-fat diet and analysed their eating behaviours. They found that: first, the stressed mice ingested food at a higher rate than the non-stressed mice, and second the stressed mice gained a lot more weight than non-stressed mice under the same diet.
Maria Razzoli, the lead author of the study, concluded that the mice developed an increased appetite shortly after exposing the mice to stress. Under the same high-fat diet, the stressed mice were more vulnerable to having a stroke, becoming obese, and developing Type-2-diabetes than the non-stressed mice. “The outcome of the CSS model resembles many features of human [binge-eating disorder],” added Razzoli.
Stress plays a big role in how hungry humans feel. In the short-term, stress shuts down our appetite. The nervous system tells the adrenal glands (an organ responsible for hormone production) to release adrenaline (Harvard Health, 2021). This activates our “fight” mode and increases our blood pressure and heart rate, enlarges our eye pupils, and decreases our appetite.
In the long-term, stress increases our appetite. The nervous system tells the adrenal glands to release cortisol. Cortisol alters blood sugar levels and triggers symptoms of low metabolism and weight fluctuation (Veeravagu, 2020). When humans live under constant stress, levels of cortisol remain high. This prevents insulin from interacting with our cells. Insulin helps our cells absorb glucose and break it down into energy (Mayo Clinic, 2019). When insulin is blocked, our blood sugar and weight increases.
Stress is something we can’t avoid in our lives. But does it influence the type of food we eat?
In 2015, researchers at Yale University published a study in the Journal of Health Psychology that investigated the relationship between chronic stress, food cravings, and body mass index (BMI). Researchers measured all of the participant’s BMI and had them fill out two surveys that assessed their chronic stress and food cravings. In the chronic stress survey, participants rated their perceived difficulty with ongoing interpersonal, social, and financial relationships from “not true” to “true.” In the food craving survey, they rated how often they craved high-fat foods, sweets, and fast-food fats over the past month from “never” to “always/almost every day.” Researchers found that chronic stress was correlated with high-fat food cravings and higher BMI.
Ariana Chao, lead author of the study, concluded that stress increases cravings for non-nutritious foods. “[Our findings] suggest that creating interventions to help adults cope with stress and with food cravings may help them attain a healthier weight,” stated Chao.
Regardless of the type of food we eat under stress, cortisol will still be present and it will still make us gain weight. Chao’s solution isn’t to replace unhealthy cravings for healthier ones. Instead, she states that people should learn stress-management strategies to prevent weight gain and live a healthier life. After all, less stress means lower cortisol levels. Lower cortisol levels means stabilized blood sugar and metabolism.
Stress management aims to keep exercise, diet, sleep, and relaxation at a healthy balance (WebMD, 2020). None of these should introduce more stress into our lives. Exercise could look like taking a walk, going for a run, using the stairs instead of the elevator, parking as far from the door as possible, or cleaning the house. Diet could look like taking nutrients that lessen the effects of stress such as Vitamin C, Magnesium, or Omega-3 fatty acids. Relaxation could look like meditating, taking deep breaths, or making time to hang out with friends and family.
My life changed when I transitioned from my first to second year of university. I went to the gym more often, I stopped pulling all-nighters, and I started bringing healthier snacks to class. My face went from looking like an inflated balloon to looking like an inverted egg. Baby steps. There was one thing I didn’t anticipate at the end of my second year: I focused a lot more and got better grades.