2.3. Nutritional Intervention
POLAND
Each participant in the study was asked to maintain a food diary, where the type and amount of food consumed daily for 14 days were recorded. A nutritional calculator from the Kcalmar.Pro-Premium app (Hermex, Lublin, Poland) was used to estimate the average daily TRP intake based on the National Institute of Public Health’s guidelines. Patients were advised to follow a balanced diet with a caloric value of 2000 kcal containing a minimum of 50 g of protein, 270 g of carbohydrates, and 70 g of fat. On the day of evaluation, everyone was given a diet with a pre-calculated TRP content. Then the patients were randomly divided into two groups of 40 each, meaning IIA and IIB. For Group IIA, the FODMAP diet was recommended for 8 weeks, after educational instruction. The patients in Group IIB were instructed to follow a low-TRP and FODMAP diet with a reduction of tryptophan intake by at least 25% compared to the initial results for 8 weeks. In the recommended diet, optimal amounts of protein, carbohydrates, and fats were maintained, and a reduction in TRP intake was achieved by excluding or drastically reducing products high in TRP such as wheat bread, sweets, hard cheeses, light and dark meats, and fish, as well as raw fruits and vegetables. The use of any drugs was forbidden. Patients from both groups received a list of all consumed products with TRP and caloric value per 100 g of product. Patients remained under dietitians’ supervision at the entire time and maintained food diaries meticulously. Caloric intake and tryptophan intake were analyzed weekly to assess adherence. After 8 weeks, follow-up medical examinations with assessment of psycho-somatic symptoms and routine laboratory tests were performed. The research was performed as an open-label clinical trial.