Photo: Studer-T. Veronika/Getty Images

2 of 7
A Blue Mood
A 2016 study of more than 12,000 people in Australia found that eating more fruits and vegetables was linked to increased happiness, satisfaction, and well-being. One explanation is that they are abundant in certain antioxidants that research indicates may be associated with optimism. The Mediterranean diet, characterized by the use of olive oil, has also been shown to decrease depressive symptoms. Again, healthy fats may help lower inflammation, which may protect against changes in the brain that lead to mood disorders.