How Food Can Affect Your Mood
What you do (and don’t) eat can affect your stress level and more

Illustration by Gloria Diianni
As the days shorten and the holidays approach, you might feel the urge to decorate your home, splurge on new clothing, … or dive into a humongous bowl of mac and cheese.
A host of factors can influence our dietary choices, but nutrition experts say that we should choose wisely not just for optimum physical health, but also to help keep our mood on an even, upbeat keel.
Tweaks to our diet can boost levels of serotonin, for example, one of the “happy hormones,” says Michelle R. Smith, MS, RDN, LD, a nutrition counselor and wellness educator at Concord Hospital’s Center for Health Promotion. Research indicates that certain vegetables stimulate serotonin release in the body, Smith says, making us less vulnerable to stress. Americans typically fall short of the recommended five to nine daily servings of fruits and vegetables, eating an average of only three servings per day. (A serving equals roughly a baseball-sized amount — about half a cup to a cup of fruit, or one cup of raw or half a cup of cooked vegetables.)
Heart-healthy fats — specifically omega-3 fatty acids — can also provide a leg up on gaining and maintaining a bright outlook. Omega-3s are present in seafood such as salmon, tuna, and bass, but they also occur in certain plant-based food such as flaxseed and chia seeds. Monounsaturated fat in avocados, olive oil, and nuts can similarly benefit mood, Smith says. “The key is balancing it and having complex carbs like whole grains with your fats and vegetables.”
In addition to increasing serotonin in the body, a diet that incorporates healthy fats keeps in check levels of the “hunger hormone” ghrelin, so you feel full longer. Additionally, it reduces oxidative stress, Smith says, making us less vulnerable to disease.
Of course, it’s not always easy to resist the siren call of what we think of as comfort foods, which are often loaded with refined carbohydrates, sugar and fat. Instead of reaching for baked goods or white, refined options such as white bread or pasta, grab a trail mix of nuts and seeds, or yogurt, which can satisfy a sweet tooth, says Michelle Olsen, RDN, LD, a registered dietitian at the Elliot Center for Advanced Nutrition Therapy in Manchester. “I’m a big fan of yogurt, Greek yogurt, [and] making a smoothie with a scoop of cocoa and a scoop of peanut butter, some milk, and a frozen banana — that’s all real food that can kind of make someone feel like they had a chocolate shake but it’s more nutritional than that.”
And don’t skip meals. Having nutritional gaps in our diet can wreak havoc with our mood, leaving us vulnerable to stress and the temptation of unhealthful foods. Research shows that skipping breakfast, for example, can put a damper on mood and energy level later in the day.
A skipped meal or a poor-quality diet can also bring on headaches. “A highly refined, processed diet is not feeding the brain,” Olsen says. A lack of protein can make us hungry and less able to think clearly. “Most people think they’re getting a headache from stress,” Olsen says, “but it could be really from just not feeding their brain appropriately, not getting the protein and the fresh fruits and vegetables and whole grains.”
Stressed, hungry, and headachy, it’s particularly easy to grab something from a vending machine and perhaps down some coffee for a quick boost, Olsen says, only to feel lousy again in an hour. If this is you, check your diet. “Protein is key,” Olsen says. “It levels off everything. It levels off our blood sugar, it levels our hunger.”
When we do eat the right things, the effects can be quick and readily discernable. “The simple change of changing an afternoon snack, going from something like a bag of pretzels to a slice of whole-grain bread with peanut butter,” Olsen says, “can make a difference for people. They can feel it in their workday.”
Making smart food choices “definitely” helps our mood and our ability to handle stress, Smith says. “The key is not to starve yourself, not to skip a meal,” she says. “Stay nourished and focus on having a balance of food choices at each meal so that if you are under a stressful situation, you’ll be less likely to react to it.”