Primary health care-level interventions targeting health literacy and their effect on weight loss: a systematic review.

Enhancing individual's health literacy for weight loss is important in addressing the increasing burden of chronic disease due to overweight and obesity. We conducted a systematic review and narrative synthesis to determine the effectiveness of lifestyle interventions aimed at improving adults' knowledge and skills for weight loss in primary health care. The literature search included English-language papers published between 1990 and 30 June 2013 reporting research conducted within Organisation for Economic Cooperation and Development member countries. Twelve electronic databases and five journals were searched and this was supplemented by hand searching. The study population included adults (≥18 years old) with a body mass index (BMI) ≥25 kg/m(2) and without chronic disease at baseline. We included intervention studies with a minimum 6 month follow-up. Three reviewers independently extracted data and two reviewers independently assessed study quality by using predefined criteria. The main outcome was a change in measured weight and/or BMI over 6 or 12 months.