Energy and Nutrition in IBD

Inflammatory bowel disease (IBD), encompassing Crohn's disease and ulcerative colitis, is a chronic, relapsing condition characterised by gastrointestinal inflammation that profoundly affects nutritional status, dietary intake, and overall quality of life. Patients with active IBD frequently experience altered energy metabolism, malnutrition, and significant reductions in food-related and disease-specific quality of life. Despite the central role of nutrition in IBD outcomes, the precise energy requirements of patients with active disease — and how these change following the induction of remission with biologic therapy — remain incompletely understood. Biologic therapies, including anti-TNF agents, anti-integrins, and IL-12/23 inhibitors, have transformed the management of moderate-to-severe IBD, achieving mucosal healing and sustained remission in a significant proportion of patients. Remission is associated with resolution of systemic inflammation, improved nutrient absorption, and restoration of gut integrity. However, the metabolic consequences of this transition from active disease to remission have not been well characterised. Understanding how caloric requirements shift as patients move from a pro-inflammatory to a quiescent disease state has important implications for nutritional support, dietetic management, and patient education. This project will prospectively assess the energy requirements of patients with moderate-to-severe IBD at two key time points: prior to commencing biologic therapy during active disease, and following the achievement of clinical and biochemical remission. Resting metabolic rate will be measured using indirect calorimetry via a ventilated hood system, a validated approach that provides accurate, individualised assessment of resting energy expenditure. This methodology will allow us to move beyond population-based predictive equations and capture the true metabolic demands of IBD patients across the disease activity spectrum. In addition to metabolic assessment, the project will examine the relationships between disease activity, nutritional status, and patient-reported outcomes. Validated instruments will be used to assess food-related quality of life — capturing the complex interplay between dietary restriction, fear of eating, and social participation — alongside IBD-specific quality of life measures including the Short IBD Questionnaire (SIBDQ) and the IBD-Control instrument. Symptom burden will be assessed using established indices appropriate to disease subtype, including the Harvey-Bradshaw Index for Crohn's disease and the Simple Clinical Colitis Activity Index for ulcerative colitis. Correlations between these domains will be explored to better understand how improvements in disease control translate into measurable gains in nutritional wellbeing and quality of life. This project offers the opportunity to work within a well-established IBD unit with access to a large cohort of patients commencing biologic therapy. The student will develop skills in clinical research methodology, nutritional assessment, patient-reported outcome measurement, and statistical analysis. The findings have direct translational relevance, with the potential to inform clinical guidelines around nutritional monitoring and dietetic support in patients with IBD commencing biologic therapy. This project is suitable for a student with an interest in gastroenterology, clinical nutrition, or chronic disease management. No prior research experience is required, though a background in medicine, nutrition, dietetics, or biomedical science would be advantageous. The project will be co-supervised by Erin Russell (Dietician), and will be conducted in collaboration with gastroenterology and dietetic staff. It will involve direct patient contact in both inpatient and outpatient settings.