Changes in Nutritional Outcomes After Sleeve Gastrectomy: a Systematic Review and Meta-analysis

Area of Science:

• Bariatric Surgery
• Nutritional Science
• Obesity Management

Background:

• Obesity is a complex metabolic disorder associated with numerous health complications.
• Sleeve gastrectomy (SG) is a common bariatric procedure for weight loss.
• Nutritional status changes after SG require careful evaluation.

Purpose of the Study:

• To conduct a meta-analysis evaluating changes in key nutritional indicators in individuals with obesity before and after SG.
• To assess the impact of SG on serum levels of 25-hydroxyvitamin D, calcium, phosphorus, iron, vitamin B12, folate, magnesium, and zinc.

Main Methods:

• Systematic literature search across major databases (PubMed, Embase, Web of Science, CNKI).
• Inclusion of 38 studies evaluating specified nutritional indicators pre- and post-SG.
• Statistical analysis using standardized mean differences (SMD) and confidence intervals (CI).

Main Results:

• Significant increases observed in serum 25-hydroxyvitamin D, phosphorus, iron, and folate post-SG.
• Significant decrease noted in serum zinc levels after SG.
• No significant changes in serum magnesium; however, calcium and vitamin B12 decreased in the unprescribed subgroup.

Conclusions:

• SG leads to improved serum levels of 25(OH)D, phosphorus, iron, and folate, particularly with monitoring and supplementation.
• Zinc levels significantly decrease post-SG, and calcium/B12 may decline without supplementation.
• Further research is needed to establish optimal supplementation protocols for minerals and trace elements post-SG.