Eating so-called comfort foods with large amounts of fat and sugar has been shown to vastly improve people's moods. A report in the Journal of Behavioral and Brain Science suggests that drawing pictures of unhealthy food can also have positive effects on mood.

From September to November 2012, researchers recruited 61 students from St. Bonaventure University in upstate New York. The subjects included 22 men and 39 women in their early 20s. Most were slightly overweight based on measurements of body-mass index, or BMI. Daily...