The association between loneliness or social isolation and food and eating behaviours: A scoping review

Loneliness or social isolation and food/eating behaviours have important health consequences and there are rationales for why they could interact. Loneliness and dietary behaviours are recognised as health determinants and targets for interventions at individual, group and population levels. However, there are currently no research reviews investigating associations between these areas. This scoping review synthesized evidence investigating loneliness or social isolation and food/eating behaviours in people aged over 16 years in high-income countries. A systematic search of five databases from 2000 was conducted using predetermined search terms. Dissertation database and backwards citation searches were also conducted. Full text screening of 254 articles/theses resulted in inclusion of three qualitative and 26 quantitative studies, with eight conducted in COVID-19 lockdowns. Almost all studies reported a relationship between loneliness/social isolation and eating behaviours usually considered harmful such as low fruit and vegetable intake and lower diet quality. Qualitative research also supports the detrimental influence of loneliness or social isolation on eating. Study quality was considered, and interpretation and comparison of results was complicated by use of varying methods. Better awareness and understanding of the relationship between these complex aspects of health is needed to inform the development of interventions and practice of nutrition and mental health practitioners, policymakers, researchers and end-users.