Two investigators independently abstracted the data in
duplicate using a standardized data collection form. The
following data were collected: article title, primary author’s
name, year and source of publication, country of origin,
study design (parallel, cross-over, or factorial trial), blinding
(open, single, or double), dietary composition, loss to
follow-up, intention-to-treat analysis, characteristics of the
study population (sample size, age, sex, prior disease status,
and baseline levels of metabolic risk factors), and the net
changes in metabolic risk factors with measures of variance,
overall and by prespecified subgroups. Disagreement
was resolved by consensus with additional investigators.