Ever thought why we reach for ice cream, pizza and other fatty foods when we’re feeling down? There may be a scientific reason. A new research has suggested that fatty foods literally serve as ‘comfort’ foods and help lift our mood.

The findings could explain why so many people become obese when facing stressful situations.

Dr. Lukas Van Oudenhove from the University of Leuven, in Belgium, and his colleagues used MRI scans to assess the emotional impact of fat when injected into the stomach.

They recruited 12 healthy-weight volunteers and scanned their brainwaves as they were shown a series of sad and neutral images as well as exposing them to sad and neutral music.

They then inserted either fatty acids or saline into their stomachs but didn’t tell the volunteers which was which. This meant they could bypass the effects of sensory stimulation as well as any associations to childhood foods.

The scientists found the music and expressions caused people’s moods to fall across the board. However, the levels of sadness among those who consumed fatty acids were around 50 per cent lower compared to those who received saline.

"Eating fat seems to make us less vulnerable to sad emotions, even if we don’t know we’re eating fat,” the Daily Mail quoted Oudenhove as telling HealthDay.

The researchers said their findings could have important implications for people with obesity, eating disorders and depression.

The study is published in the Journal of Clinical Investigation.