EFFECTS OF MEDICAL NUTRITION THERAPY ON NUTRITIONAL REHABILITATION, NUTRIENT BALANCE, AND CARDIOVASCULAR RISK IN HOSPITALISED PATIENTS WITH EATING DISORDERS: A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract

Background: Eating disorders, particularly anorexia nervosa (AN), bulimia nervosa (BN), avoidant/restrictive food intake disorder (ARFID), and atypical AN, represent severe psychiatric conditions with significant medical complications. Medical nutrition therapy (MNT) is a cornerstone of inpatient treatment, yet optimal refeeding strategies, cardiovascular safety, and metabolic outcomes remain areas of active investigation.

Objective: To systematically evaluate the effects of MNT on nutritional rehabilitation outcomes (weight restoration, BMI recovery), nutrient balance (macronutrient and micronutrient status), and cardiovascular risk markers (QTc interval, ECG abnormalities, lipid profiles, blood pressure) in hospitalised patients with eating disorders, and to assess refeeding syndrome incidence and electrolyte management strategies.

Methods: We conducted a systematic review following PRISMA guidelines. Comprehensive searches were performed across multiple databases for studies examining MNT interventions in hospitalised patients with AN, BN, ARFID, and atypical AN. Studies were screened using predefined PICO criteria. Data extraction included study design, patient characteristics, MNT protocols (caloric prescription, macronutrient composition, delivery method), weight restoration outcomes, cardiovascular parameters, refeeding syndrome incidence, and electrolyte disturbances. Risk of bias was assessed using the Cochrane Risk of Bias 2 (RoB 2) tool for RCTs and adapted Newcastle-Ottawa Scale for observational studies. Meta-analysis was planned for outcomes with sufficient homogeneity using random-effects models. GRADE methodology was applied to assess certainty of evidence.

Results: The search identified 279 unique papers, with 30 studies meeting inclusion criteria. Studies predominantly examined AN populations (n=26 studies). Sample sizes ranged from 10 to 386 patients, with mean baseline BMI 11.2-17.4 kg/m². Higher-calorie refeeding protocols (≥14 00 kcal/day initial) were associated with faster weight restoration (mean 0.76-1.98 kg/week) and shorter hospital stays compared to conservative approaches. Cardiovascular monitoring revealed high prevalence of baseline abnormalities: bradycardia (35-95%), QTc prolongation (~25%), pericardial effusion (10.5-27%), and left ventricular dysfunction (15-52%). Most cardiovascular abnormalities demonstrated reversibility with nutritional rehabilitation. Refeeding syndrome incidence ranged from 0-14%, with hypophosphatemia occurring in 14-45% of patients. Prophylactic electrolyte supplementation protocols were widely implemented.

Conclusions: Medical nutrition therapy effectively achieves weight restoration and medical stabilization in hospitalised patients with eating disorders. Higher-calorie refeeding approaches (≥14 00 kcal/day) appear safe and effective under close medical monitoring with prophylactic electrolyte supplementation, achieving faster weight gain without increased refeeding syndrome risk (moderate certainty). Cardiovascular abnormalities are common at admission but largely reversible with nutritional rehabilitation (low certainty). Standardized protocols incorporating daily electrolyte monitoring, prophylactic phosphate supplementation, and cardiovascular surveillance are essential for safe refeeding. Future research should prioritize RCTs comparing refeeding strategies, long-term cardiovascular outcomes, and evidence-based protocols for severely malnourished patients.