When healthcare practitioners remind us that “we are what we eat,” that applies to our emotional well-being as well as our physical bodies. During the winter, experts suggest we should alter our diet to accommodate darker days. We rely on our biological clock to regulate our mood, and less overall sunlight can throw that natural rhythm off kilter.

According to Insider, nutritionist Natalie Olsen says that certain additions to our diet can help us feel better during colder, shorter days and reduce the likelihood of seasonal affective disorder, or SAD. Her first choice are foods rich in omerga-3 fatty acids, which reduce inflammation caused by stress and negative feelings. Fatty fish like salmon, mackerel, and herring are excellent sources of omega-3 fatty acids. Aim for two servings weekly.

Nuts and seeds are also rich in omega-3s. says Olsen. Walnuts, flax seeds, chia seeds and hemp seeds are great sources and help combat inflammation.

Berries are natural sources of sweetness that don’t trigger the highs and lows of adding extra sugar to your diet, says Everyday Health. Drinking tea instead of coffee provides a dose of caffeine and is associated with a 31% lower risk of depression, according to a review published in the journal Nutrients. That may be due to tea’s unique compounds, including teasaponin, L-theanine, and EGCG, all of which affect the neurotransmitter dopamine, reduce inflammation, and lessen the stress response, according to researchers.

Adding high-fiber foods to your diet helps keep your gut microbiome healthy, and research shows that a balance of good “gut bugs” is important to mental health. Eat plenty of plant-based foods like beans to reinforce gut health. “These help boost short-chain fatty acids, which are tied to potentially lowering inflammation in the body and could even stimulate the production of serotonin,” says registered dietitian nutritionist Ginger Hultin, author of Anti-Inflammatory Diet Meal Prep. Serotonin is a neurotransmitter that helps modulate mood.eHer

Dark chocolate is another feel-good food that helps boost your mood because it triggers a temporary serotonin rush to the brain, according to Everyday Health. It’s sweet but doesn’t contain a ton of sugar. Look for dark chocolate that contains at least 70% cocoa.

Stock up on vegetables like kale, collard greens, bok choy and other leafy greens that are packed with B vitamins that are critical for brain function, says Hultin. Researchers have found that an overall deficiency in these vitamins is associated with mood disorders in some people, says Insider. Supplementing with B vitamins was found to lower stress levels, which can contribute to winter doldrums.