Study selection and data extraction
Studies were eligible for inclusion in the review if they were published, peer-reviewed, English language articles describing a worksite-based weight loss and/or healthy
eating intervention with a minimum study duration of eight weeks. All study designs were eligible. To be eligible for inclusion, articles had to report one or more dietary outcomes (e.g. energy, fat, fruit or vegetable intakes) assessed using an accepted, validated method of dietary assessment at eight weeks or later following baseline. The review was restricted to English language articles. One author (LMA) reviewed the titles, abstracts and keywords of every record retrieved and the full article
was retrieved for further assessment if available information suggested that the study was eligible for inclusion. A standardised data extraction form was then completed for all eligible studies. Data were recorded on country of origin, type of worksite, participant characteristics,study design, intervention characteristics, study outcome measures, and reported results. Study quality was assessed using a checklist adapted from a previous review [12] and included assessment of use of a control group, randomisation, and study attrition rates. For controlled trials, assessment was made of concealment of randomised allocation, blinding, use of intention-to-treat analyses, and similarity of baseline characteristics of participants.