Caloric and protein restriction diet for induction treatment of Crohn's disease

INTERVENTION: The CRPR diet consists of an estimated 70% of the individuals required calories and 20% of the individuals protein (12), based on the basal metabolic rates and on the daily energy requirements (DER) as calculated with the Harris‐Benedict equation (14) and with the BODPOD (the Gold Standard Body Composition Tracking System is an air displacement plethysmograph which uses whole‐body densitometry to determine body composition (fat and fat‐free mass) in adults (18, 19)l. The Harris‐Benedict equation takes into account sex, height, age, body weight and estimated activity level. Normal protein intake is set at 20% of the total calories based on the DER. To facilitate the dietary requirements, participants will receive calorie‐ and protein‐restricted powder shakes (Scandishake® Mix) as the main component of the diet, which can be supplemented with a limited amount of protein‐restricted products (mainly fruits and vegetables) until the desired individual energy content of the diet is reached. CONDITION: IBD, Crohn's disease PRIMARY OUTCOME: Proportion of patients with clinical remission after 4 weeks of dietary intervention. Clinical remission will be defined as a Harvey Bradshaw Index (HBI) < 5. SECONDARY OUTCOME: ‐ Proportion of patients with clinical response. Clinical response will be defined as HBI reduction ≥ 3. ; ‐ Feasibility; proportion of patients that have maintained the diet throughout the trial period, combined with the compliance. Feasibility will be defined as >70% adherence to the protocol (based on known drug adherence rates in this study group, which is 66%). Compliance to the diet will be assessed by serum (pro)‐albumin, urea and retinol binding protein. ; ‐ Proportion of patients with biochemical remission. Biochemical remission will be defined as CRP ≤10 mg/L and a faecal calprotectin 200≤g/g. ; ‐ Proportion of patients with relapse of CD (necessitating surgery, (re)introducing biologics, corticosteroids or IS). ; ‐ Changes in bristol stool scale ; ‐ Changes in grip strength ; ‐ Changes in % fat, % free fat mass, fat mass in kg, free fat mass in kg, body mass, body volume and body density as measured by BOD POD‐ Qualify of life measured by IBDQ ; ‐ Safety and tolerability of the low caloric low protein diet will be assessed by VAS scores by PROM: PRO‐2 (abdominal pain and stool frequency). and adverse events. ; ; Molecular markers: ; ‐ Changes in CRP and faecal calprotectin (FCP) ; ‐ Changes in molecular factors (leptin, HO‐1, GST, H2S) and microbiome. INCLUSION CRITERIA: ‐ Crohn's disease ‐ Active mild to moderate disease (defined as an endoscopic SES‐CD score ≥ 6 or in case of exclusive ileal disease ≥ 4, after ileocoecal resection a Rutgeert's score >i2 and a HBI score between 5 and 10) ‐ Age between 18 ¨C 70 years at baseline