Incorporation of Evidence-Based Practical Dietary Therapy into Inflammatory Bowel Disease Care: The DELECTABLE Program

Dietitian-led, Open-label program of 3 dietary strategies as adjunctive therapy for Inflammatory Bowel Disease. Dietary therapy will be offered to patients: the Crohn’s Disease Exclusion Diet (if the patient has Crohn’s or pouchitis), the Ulcerative Colitis diet (if the patient has UC or microscopic colitis), or a less restrictive wholefood diet that excludes ultra-processed food (for any condition). The Crohn’s Disease Exclusion Diet (CDED) The Crohn’s Disease Exclusion Diet (CDED) is a 3-phase diet. The diet mainly focuses on: • Avoidance of added chemicals • Inclusion of high-quality, low-fat protein (mostly chicken and eggs) • Inclusion of resistant starch and specific fibres (apples, bananas, potatoes) • Use of liquid supplements to help meet energy and nutrient needs In addition, the diet limits dairy, wheat, oats, quinoa, red meat, and fish. These must be avoided entirely in the first six weeks and consumed in restricted amounts long term. Certain fruits and vegetables are also restricted in the initial phase of the diet. The diet becomes less restrictive as you move through the stages. In brief: • Phase 1: Follow for 6 weeks, every day consume 50% of your energy as liquid supplements, and eat eggs, chicken, potatoes, apples, and bananas daily. Plus, eat unlimited rice, rice noodles and limited amounts of some fruit and vegetables • Phase 2: Follow for 6 weeks, every day consume 25% of your daily energy as liquid supplements and eat eggs, chicken, potatoes, apples, and bananas. Plus, eat unlimited rice, rice noodles, and start introducing some additional grains, fruits, and vegetables not allowed during phase 1. • Phase 3: Follow longer-term, follow the CDED guidelines for 5 days of the week and consume some disallowed foods in moderation on the other 2 days. The Ulcerative Colitis Diet The researchers designed the ulcerative colitis diet. The focus of this diet is: • Avoid sulphur, sulphide-additives, sulphur-containing vegetables and sulphur-containing amino acids (cysteine, taurine, methionine). • Reduction in saturated fats • Provision of fermentable carbohydrates. Like the wholefood diet, the Ulcerative Colitis diet limits intake of added chemicals in food. The Wholefood Diet This diet was designed by the researchers. This diet's main focus is on excluding added chemicals in food. Most processed foods contain chemicals to make them look better, last longer, or taste different. Many of these chemicals, however, are known to be pro-inflammatory. Natural (unprocessed) foods are allowed. Natural foods include fresh, chilled and frozen fruits and vegetables; legumes such as beans and lentils; nuts and seeds; fresh meat, poultry and fish; eggs; milk and some yoghurts. Grains, such as oats, rice, polenta, quinoa and flours/flakes/pastas made from grains are also considered natural, as although they have undergone some mechanical processing, they generally contain no chemical additives. Processed food ingredients generally do not contain added chemicals and can be kept in the diet. These are usually used to cook fresh foods and are rarely consumed alone. Examples include olive and other vegetable oils (sunflower, canola, etc.), salt, sugar, honey and vinegar. Processed foods with these minor additions (i.e. salt, sugar, oil) but no chemicals can also be kept in the diet. Examples include some corn chips, potato crisps, nut butters, and certain crackers/breads/breakfast cereals. Processed foods often contain additives to preserve their original properties or prevent spoilage. Examples include tinned vegetables and fruits, cured meats, cheese and bread. The labels of these foods need to be checked before deciding if they are safe to consume. Adherence will be monitored using 24-hr diet recalls, a modified medication adherence scale, and the CDED adherence scale. Patients will have in-person or phone visits with the dietitian at Baseline, end of Week 1, End of Week 6, End of Week 12, 6 months and 12 months post-enrollment, with follow-up (completion of questionnaires) at 24, 36, 48 and 60 months. After 12 weeks, all patients will be transitioned to the wholefood diet. Patients will also be permitted to switch diet arms during the program, which will be recorded. Patients will follow their allocated diet arm for the entire duration that they are allocated to that diet (all meals and snacks). Dietitians will provide education materials and a meal plan, but food will not be provided.