Depressing fact that eating junk food can leave you feeling low

Scientists have found a link between consuming harmful trans-fats and an increased risk of depression. But olive oil and healthier polyunsaturated fats appear to have the opposite effect, helping to keep people cheerful.

The research may provide a clue to why southern Europeans tend to be less depressed than northerners, say the researchers.

Mediterranean diets are rich in healthy ingredients such as fish, fresh fruits and vegetables, as well as olive oil.

People in the UK and other northern European countries, on the other hand, are more likely to consume foods laden with saturated and trans-fats. Trans-fats are modified vegetable fats used to improve shelf-life and often found in fast foods, pastries, cakes and biscuits.

The research by Spanish scientists showed that people who ate high levels of trans-fats were up to 48 per cent more prone to depression.