A new study indicates that a diet rich in ultra-processed foods and refined carbohydrates may increase the risk of depression and other mental health conditions. The research has been published in the Journal of the Academy of Nutrition and Dietetics. Kristin Kirkpatrick, a nutritional psychologist and registered dietitian, said there is "a tremendous amount of high-quality data linking food to beneficial (or worsening) mental health outcomes". Ms Kirkpatrick advised people to reduce the amount of sugary and low-fibre food they eat to lessen the chances of developing mood disorders. She wrote: "Limits should be made on sugar, refined grains, ultra-processed foods, and alcohol."

Ms Kirkpatrick also advised people to increase their intake of high-fibre and fermented foods. She said the plant-based Mediterranean diet has been shown to be effective in reducing depression. She said the diet included "omega-3 fatty acids, colourful plants like berries, extra virgin olive oil, leafy greens, and lean sources of protein". She added that the diet "has been shown to assist with both depression and anxiety". Related research from Professor Felice Jacka at Deakin University in Australia corroborated Ms Kirkpatrick's findings. Dr Jacka said fermented, probiotic foods may influence brain-related biology and lead to more positive moods and enhanced learning.