Natural-foods fans know that conventional food products are making our nation sick, contributing to diabetes, childhood obesity, high cholesterol—the list goes on. What is less well-known, but increasingly documented, is how what we eat affects our mood.

In 2012, antidepressants were the second most prescribed drug in the United States, just behind cancer medications, according to the IMS Institute for Healthcare Informatics. Spending on mental-health pharmaceuticals hit $23.5 billion, representing nearly 22 million people and 329 million mental-health-related prescriptions. Contrast this with $188 billion—the projected amount of quick service restaurants sales this year, according to The National Restaurant Association, and an argument for “you are what you eat” begins to emerge.

Nutrition science identifies many foods that offer mental boosts without pharmaceuticals’ harmful side effects. “Good-mood foods allow your body to produce greater amounts of serotonin [the body’s feel-good chemical],” says Mary Bernt, a 27-year vegan and international nutrition lecturer. “The science of nutrition—never the correct answer on tests in medical school—goes back to Hippocrates’ saying: ‘Let food be your medicine and medicine be your food.’” Stock up on the following foods to put you in a positive frame of mind, and try them out in our suggested recipes at deliciousliving.com.

Flaxseed and walnuts. In a 2013 animal study, flaxseed’s natural phytoestrogens reversed depressive-like behavior, with no adverse side effects. Flaxseed also offers alpha-linolenic acid (ALA) omega-3s, well-researched antidepressive nutrients. Scientists laud antioxidant-rich walnuts, another ALA source, for battling postpartum depression, manic-depressive psychosis, and even dementia. Eat a mere 1.5 ounces of walnuts daily—about a handful—for benefits.

Try them in: Flaxseed and Pomegranate Smoothie; Cherry-Walnut Bites

Fish. Omega-3 fatty acids EPA and DHA, found in cold-water fish (such as salmon and sardines) and fish oil supplements may ward off depression even better than plant-based ALA because they are more bioavailable, according to a 2010 study in Bipolar Disorder.

Try it in: Nori-wrapped Glazed Salmon with Sesame Kale; Broiled Sardines with Fennel and Olives

Okra. This often-overlooked vegetable is a treasure trove of neuroprotective, antidepressant compounds. Full of soluble as well as insoluble fiber, okra feeds “good” gut bacteria, which researchers increasingly believe influence mood, motivation, higher cognitive functions, and overall brain health. A 2011 study also suggested gut microbiotics could alleviate stress-related disorders.

Try: Pan-Seared Okra

Yeast. In 2009, scientists investigated the antistress effects of hydrolyzed yeast; after three days of taking it, participants showed “psychologically stable” brain maps, and after two weeks, their depression and anxiety markers improved. Get yeast’s mood-lifting B-complex vitamins by mixing nutritional yeast flakes with cashew or almond butter, forming into balls, and rolling in toasted sesame seeds; or sprinkle directly over hot popcorn.

Try it in: Mocha Chip Muffins

Kale. Bernt’s favorite mood-enhancing recipe? Raw kale salad. “I feel so good when I eat raw kale. Plus, I run a café and there’s stress involved with that, so I love stripping kale off the stems.” In addition to providing a way to vent aggression, kale also delivers a little ALA and a huge dose of anti-inflammatory vitamin K, valuable because new research points out a clear link between chronic inflammation and mental disturbances such as depression.

Try it in: Raw Kale Salad with Pumpkin Seeds