Study designs of evaluations included in the review
Randomised controlled trials (RCTs) were eligible for the review. The included study was a 6-week, placebo-controlled RCT.
Specific interventions included in the review
Studies of citrus aurantium (also known as 'bitter orange' and 'sour orange') used alone or with other ingredients, compared with placebo, were eligible for the review. Studies that examined citrus aurantium in combination with ephedrine alkaloids, a weight loss product banned by the Food and Drug Administration in 2004, were excluded. The participants in the included study were randomised to one of three groups: the intervention group received a herbal mixture containing citrus aurantium, St. John's Wort and caffeine; the placebo control group received a maltodextrin placebo; and the third group was a no-placebo control. The participants in all three groups also received dietary counselling and participated in a 3 days per week exercise programme.
Participants included in the review
The only inclusion criteria stated for the participants was that they had to be human. The participants in the included study were healthy but with a body mass index of over 25 kg/m2.
Outcomes assessed in the review
Studies that reported the outcome of change in weight were eligible for the review. The outcomes assessed in the included study were change in weight, percentage body fat, fat mass and basal metabolic rate, measured at baseline and 3 and 6 weeks.
How were decisions on the relevance of primary studies made?
Two reviewers independently assessed studies for inclusion in the review.