Background: Research indicates that food parcels provided by food banks are nutritionally poor. Food insecurity and the use of food banks are both rising, with detrimental effects on the dietary intake and health of users. This mixedmethod systematic review aims to investigate the current nutritional adequacy of pre-packaged food parcels and whether using food banks reduces the food insecurity and improves the dietary intake of their users. Methods: A mixed-method systematic literature review, restricted to articles published from 2015, was conducted using eight electronic databases, four grey literature databases and eight relevant websites. Quantitative findings, investigating the nutritional quality of food parcels and/or their impact on dietary intake or food insecurity, were presented narratively. Qualitative findings reporting the views of food bank users regarding food from food banks underwent thematic synthesis. These independent syntheses were integrated using configurative analysis and presented narratively. Results: Of 2189 articles, 11 quantitative and 10 qualitative were included. Food parcels were inconsistent at meeting nutritional requirements and often failed to meet individual needs, including cultural and health preferences. Using food banks improved food security and dietary quality of users, allowing otherwise unachievable access to food. However, food insecurity remained, and is explained by limited food variety, quality and choice. The mixed-method findings support interventions to ensure consistent, adequate nutrition at food banks, including catering for individual needs. Conclusions: Food banks are a lifeline for those severely food insecure. However when used alone, food banks struggle to eliminate the heightened food insecurity of their users. Efforts to improve the nutritional quality of food parcels could improve the experiences and diet-related outcomes of those requiring food banks.