We all know that junk food is not good for our health, but now a new study has linked the regular consumption of fast food to depression.

The study, published in the journal of Public Health Nutrition, showed that a diet that includes fast foods like hamburgers and hot dogs, or commercially baked goods like doughnuts or croissants, often results in an increased depression risk.

The researchers followed 8964 participants who didn’t have depression and weren’t taking antidepressants. Their diet and mental status were reviewed over a six month period.

The findings revealed that those who ate the most junk food had a 51 percent likelihood of developing depression compared to those who ate less junk food. Of the participants, 493 people were depressed and taking antidepressants at the end of the study period.

"Although more studies are necessary, the intake of this type of food should be controlled because of its implications on both health (obesity, cardiovascular diseases) and mental well-being," said study researcher Almudena Sánchez-Villegas.

Scientists from the Universities of Las Palmas de Gran Canaria and Granada also found that a junk food diet correlated with people who lived a sedentary lifestyle, smoked, worked more than 45 hours a week and ate other similar unhealthy foods.

And in another separate study published in the PLos One (Public Library of Science) earlier this year, findings showed that consuming foods with trans fats – found in most junk foods –could be linked to aggressiveness and irritability.

Findings showed that a greater intake of trans fats seemed to predict whether a person was more aggressive, regardless of external factors like race, gender and age.

All the research seems to point to the following simple advice: Try to limit your eating of fast or junk food, include more fresh fruit and vegetables into your diet and up your water intake.