We know it has long been bad for your waistline.

But fast food can also be bad for your mental health, according to a new study.

Eating junk such as as hamburgers, hotdogs and pizza heightens your chance of developing depression.

A study by Spanish scientists has revealed those that revel in eating fast food were 51 per cent more likely to develop depression, compared to those who ate little or none.

The study was undertaken by the universities of Las Palmas de Gran Canaria and Granada, Spain,

‘The more fast food you consume, the greater the risk of depression,’ said Almudena Sanchez-Villegas, who led the study, which was printed in the Journal Public Health Nutrition.

As well as the health problems those eating fast food were more likely to be single and less active

The sample under SUN Project (University of Navarra Diet and Lifestyle Tracking Program), comprised 8,964 participants, who had never been diagnosed with depression or taken anti-depressants.

They were assessed for an average of six months and 493 were diagnosed with depression or started to take anti-depressants.