Preoperative Carbohydrate Loading vs Fasting: Effects on Postoperative Recovery and Outcomes in General Surgery

Traditional preoperative fasting aims to reduce aspiration risk but may exacerbate catabolism and insulin resistance. Enhanced Recovery After Surgery (ERAS) guidelines often endorse preoperative carbohydrate loading (PCL) in lieu of prolonged fasting. We systematically identified all peer-reviewed, blinded, PubMed-indexed studies (2020–2025) in general surgery comparing preoperative oral carbohydrate loading versus standard fasting, with outcomes focusing on postoperative recovery time (e.g. time to flatus, oral intake, ambulation, hospital stay) and overall patient outcomes (e.g. complications, insulin resistance, patient comfort). We extracted key insights from each randomized controlled trial (RCT) and synthesized common findings and discrepancies. Six RCTs met inclusion criteria (bariatric, colorectal, and general gastrointestinal surgery). Common findings were that PCL is safe, improves perioperative comfort (reduced hunger, thirst, fatigue, anxiety), and attenuates insulin resistance and inflammatory stress responses [1]. However, effects on recovery metrics and complications varied: some trials reported shorter time to bowel function and hospital stay with PCL [2, 4], whereas others found no significant benefit [1]. In comparative synthesis, we identified five frequent commonalities (e.g. enhanced patient comfort, reduced metabolic stress) and five frequent divergences (e.g. mixed effects on length of stay and complications). Trend analysis revealed areas moving toward consensus (e.g. PCL’s safety and metabolic benefits) and away (e.g. LOS reduction), as well as emerging insights (e.g. benefits for diabetic patients when combined with insulin management). These findings were integrated into a formal meta-analysis-style report. All cited studies are RCTs in PubMed-indexed journals focusing on general surgery outcomes.