[The relationship between obesity, social isolation, and mental health-results from the LIFE adult study].

Background: Population-based studies on the relationship between social isolation and obesity, which also include younger adults, are still lacking in Germany. The aim of this study is to investigate the prevalence of social isolation in people with and without obesity. In addition, socially isolated people with and without obesity are examined with regard to socio-demographic and socio-economic factors as well as with regard to depressive symptoms.

Methods: This study was based on baseline data from the LIFE Adult Study (18-79 years) from the 2011-2014 study period. The sample comprised n = 8350 participants. In addition to socio-demographic characteristics and socio-economic status (SES), data on social isolation (LSNS-6), depression (ADS), and body mass index (BMI) were collected. Evaluations were carried out using inferential statistical analyses.

Results: Overall, 13.1% of the total sample were affected by social isolation. Participants with obesity (20.4%) had a significantly (p < 0.001) higher prevalence compared to those without obesity (11.4%). A better social integration was significantly associated with younger age (p < 0.001), female sex (p < 0.001), being married (and cohabiting) (p < 0.001), higher socioeconomic status (p < 0.001), and lower depressive symptoms (p < 0.001).

Discussion: A higher BMI was not associated per se with poorer social integration. However, the present study showed that socially isolated people with obesity represent a special risk group for impaired mental health and had twice the prevalence of social isolation compared to those without obesity.