Eligibility Criteria
Studies were selected by applying the following
Population-Intervention-Comparator-Outcomes-Study design (PICOS)
criteria 28: 1)
subjects received oral soy and soy products supplementation, as a
nutritional strategy; 2) original randomized-controlled trial researches
and 3) reporting at least one outcome measure of adipokines (adiponectin
and leptin) ; 4) presented data of interest as mean and standard
deviation (SD) of adiponectin and leptin in both intervention and
placebo groups; and 5) had a trial duration of more than 4 weeks.
Exclusion criteria were: 1) using a mixture of soy protein or
isoflavones extract only in intervention group, not including a placebo
group; 2) semi experimental, nonrandomized trials and trials without
control groups; 3) duplicate studies with the same population (several
papers reported the same data); 4) enrolled pregnant or lactating women;
5) experimental and animal studies; and 6) reviews, letters to editor,
editorial articles, or case reports.