Observational evidence suggests dietary modification may improve symptoms of anxiety. In a study following a teenager with General Anxiety Disorder and Hypoglycemia, addition of protein, fat and fibre had significantly improved their conditions. The symptoms of anxiety have decreased as well as its frequency. Briefly returning to the individual’s original diet, which consisted of refined carbohydrates, had caused a return of the anxiety symptoms. This case supports the hypothesis that dietary glycemic index affects progression of mental illness such as anxiety.
Aucoin, Monique, and Sukriti Bhardwaj. “Generalized Anxiety Disorder and Hypoglycemia Symptoms Improved with Diet Modification.” Case Reports in Psychiatry, Hindawi Publishing Corporation, 2016, www.ncbi.nlm.nih.gov/pmc/articles/PMC4963565/