The effectiveness of interventions targeting specific out-of-home food outlets: protocol for a systematic review.

BACKGROUND
Eating out of the home has been associated with higher intakes of energy and fat and lower micronutrient intakes, as well as the development of obesity. Out-of-home food outlets (OHFOs) and the foods obtained from these outlets are an ideal target for interventions to improve diet and tackle obesity. This systematic review will explore the evidence for the effectiveness of promoting healthy behaviour through interventions that modify food practices in specific OHFOs.

METHODS/DESIGN
We will search the databases MEDLINE, EMBASE, CINAHL, PsycINFO, ASSIA and the NHS Economic Evaluation Database for studies that have evaluated interventions conducted in an OHFO that aim to promote healthier menu offerings. OHFOs which are not openly accessible to the general public and supermarkets will be excluded. Included study designs will be randomised controlled trials, non-randomised controlled trials, controlled before-after studies, interrupted time series studies and evaluations of single interventions where outcome measures were assessed at least once pre and post-intervention (repeated measures studies).

DISCUSSION
This systematic review aims to synthesise the available evidence with regard to interventions that aim to change specific OHFOs in order to promote healthier menu offerings. The findings of this review will provide information on the types of interventions that have been evaluated and the context in which they are set, and provide insights into what interventions, and intervention functions, are most effective in different OHFO settings, along with any important innovation, implementation and cost implications.The review has been registered with PROSPERO (registration no. CRD42013006931).