Definitions and Assessment Methods of 'Home Cooking' in Studies with Dietary Variables: A Scoping Review

Home cooking is a complex idea that involves multiple skills and behaviors and can be interpreted differently. Using six databases (two of which were Japanese), this scoping review examined the definitions and methods used in studies investigating the relationship between home cooking and dietary variables. Of the 40 studies (2 in Japanese) included in this review, 8 provided definitions but did not specify the extent or level that convenience foods can be allowed in food preparation. The methods were classified into two categories, namely, perception-dependent (n = 29) if using a self-reported instrument, or perception-independent (n = 11) if based on investigators' classification. Subsequently, indicators of home cooking were classified based on survey attributes (e.g., frequency, location). All but five studies used single indicators, primarily the preparation frequency (n = 18). Quality of analysis was also evaluated. Studies that used multiple indicators or perception-independent methods showed high or moderate overall quality. In contrast, studies that used single indicators based on perception-dependent methods tended to have a low overall quality. The consistency of the relationship between home cooking and dietary variables depended on study quality. In conclusion, the definitions of home cooking were inconsistent across studies, and lacked consensus for examining the association between dietary outcomes.