Front of pack nutritional labelling schemes: a systematic review and meta-analysis of recent evidence relating to objectively measured consumption and purchasing

Background Front of pack labelling (FOPL) provides visible nutritional information and appears to influence knowledge and reformulation. However, a recent Cochrane review found limited and inconsistent evidence for behaviour change. The present review aimed to examine studies published subsequent the Cochrane review, focusing on prepackaged foods, examining the impact of FOPL on purchasing and consumption. Methods Controlled experimental/intervention and interrupted time series (ITS) studies were included, with no age/geography restrictions. Exposures were FOPL with objectively measured consumption/purchasing outcomes. Thirteen databases were searched (January 2017 to April 2019) and forward citation searching was undertaken on the included studies. Purchasing data from experimental studies were meta-analysed. Two series of meta-analyses were undertaken; combined FOPL versus no-FOPL and specific FOPL scheme versus no-FOPL. Outcomes were sugar (g 100 g(-1)), calories (kcal 100 g(-1)), saturated fat (g 100 g(-1)) and sodium (mg 100 g(-1)). Results We identified 14 studies, reporting consumption (experimental; n = 3) and purchasing (n = 8, experimental; n = 3, ITS). Meta-analysis of experimental studies showed sugar and sodium content of purchases was lower for combined FOPL versus no-FOPL (-0.40 g sugar 100 g(-1), P < 0.01; -24.482 mg sodium 100 g(-1), P = 0.012), with a trend for lower energy and saturated fat (-2.03 kcal 100 g(-1), P = 0.08; -0.154 g saturated fat 100 g(-1), P = 0.091). For specific FOPL, products purchased by 'high in' FOPL groups had lower sugar (-0.67 g sugar 100 g(-1), P <= 0.01), calories (-4.43 kcal 100 g(-1), P < 0.05), sodium (-33.78 mg 100 g(-1), P = 0.01) versus no-FOPL; Multiple Traffic Light had lower sodium (-34.94 mg 100 g(-1), P < 0.01) versus no-FOPL. Findings regarding consumption were limited and inconsistent. FOPL resulted in healthier purchasing in ITS studies. Conclusions This review provides evidence from experimental and 'real-life' studies indicating that FOPL encourages healthier food purchasing. PROSPERO CRD42019135743.