Table 1.

Inclusion and exclusion criteria for included studies.

Inclusion Criteria	Exclusion Criteria
Population
Total hip replacement patients	Studies on animals
Total knee replacement patients
Intervention
Pre-operative or post-operative oral nutrition	Intravenous nutritional supplementation Assessments of intraoperative blood loss
	Iron supplementation
Outcome Measure
Length of stay
Post-operative complications
Insulin resistance
Pain
Functionality
C-reactive protein
Vitamin D
Methodology
Randomized clinical trials	Review articles
Pilot randomized clinical trials	Case studies
	Cross-sectional studies
	Historical studies
	Non-randomized clinical trials
Publication
Published in English	Unpublished studies
Access to full text	Study protocols