Preoperative multi-nutrient medical food versus fasting control in adults undergoing elective surgery: a single-center pilot trial

BackgroundThe surgical stress response is a predictable, physician-managed metabolic state triggered by anesthesia and tissue injury, marked by insulin resistance and hypercatabolism that create unique nutritional needs unmet by standard, pre-surgical fasting diets. We developed a multi-nutrient medical food to support perioperative metabolic homeostasis and piloted its safety/tolerability and exploratory outcomes. MethodsIn a single-center pilot trial (n=67) of adults undergoing elective abdominal, cardiac/thoracic, gynecological, or orthopedic surgery, participants were allocated to medical food or no-treatment control. The product was taken twice preoperatively (evening before and 4 h pre-op) with standard care. Primary safety outcomes were adverse events, postoperative nausea/vomiting (PONV), 30-day readmission, and infections. Exploratory outcomes were fasting glucose, HbA1c, electrolytes, cortisol, pre-operative emotional state, and post-operative pain. ResultsAll participants completed the intervention. No product-attributed adverse events occurred. Gastric clearance was achieved within 2 h in all, and there were no 30-day readmissions or infections. PONV occurred in 30.3% vs 35.3% (risk ratio 0.86, 95% CI 0.43-1.71, p=0.796). Post-operative glycemia favored the intervention; at 48 hr the intervention group showed lower glucose (HL -9 mg/dL, g=0.35, p=0.030), while earlier timepoints were nonsignificant. Post-operative magnesium was numerically lower with intervention (4.76 vs 5.10) without statistical significance; other electrolytes and cortisol showed minimal differences. Post-operative pain was 5.33 vs 5.62 (g=0.19, p=0.43). Positive pre-operative emotion was more frequent with intervention (17/33 vs 9/34; risk ratio 1.95, p=0.046). ConclusionThe medical food was safe and well tolerated without increased PONV or readmissions. Preliminary metabolic and emotional signals justify a larger, adequately powered efficacy trial. Clinical Relevancy StatementThis pilot trial demonstrates that a preoperative multi-nutrient medical food was well tolerated and feasible to administer in a routine clinical setting: all participants achieved gastric clearance within 2 hours of the pre-operative dose, with no increase in PONV and no readmissions. Exploratory findings indicate potential benefits that could nutritionally support recovery if confirmed. These results support the feasibility of administering a targeted nutrition intervention shortly before surgery and justify evaluation in a larger efficacy trial. Clinical Trial RegistrationNCT07359222