Depression is the leading cause of disability in Americans ages 15 to 44. Now, a new study shows the foods you eat or don’t eat might affect how you feel.

Depression impacts more than 16 million adults in the United States each year. But, could something as simple as changing your diet help boost your mood?

In a new paper, researchers analyzed the results of 41 studies on depression and food. They found eating a Mediterranean diet was linked to a 33 percent lower risk of depression. The Mediterranean diet includes foods like veggies, fruits, nuts, legumes, fish, and healthy oils which contain monosaturated and omega-three fats.

“Especially the omega three fatty acids … those are known to have pretty clear effects with depression,” said Charles Conway, PhD, Washington University in St. Louis.

On the flip side, the researchers found a diet high in processed foods, sugar and saturated fats upped the risk of depression. Steer clear of products with ingredients like flour, hydrogenated oil, sugar, artificial sweeteners, and high fructose corn syrup. Some foods that have been shown to boost your mood: avocados, berries, tomatoes, leafy greens like kale and spinach, walnuts, seeds, and beans.

And don’t forget to throw in some physical activity for good measure.

“Pushing yourself to exercise regularly probably helps with some degree of mood improvement,” continued Dr. Conway.

Some researchers theorize that food affects your mood because it changes your gut bacteria. If you continually consume processed or “inflammatory” foods, you’re creating chronic inflammation in the body that can lead to depression