Table 2.
Data Extraction
| First Author | Country | Assessment of Obesity | Assessment of Loneliness or Social Isolation | Study Type | Sample Description | Sample Size | Age | Females in Total Sample | Results |
|---|---|---|---|---|---|---|---|---|---|
| Hajek (2020a)17 | Germany | BMI > 30 kg/m2 | Revised UCLA Loneliness Scale (three items) | Longitudinal (three waves, 2013–2017) | Survey of Health, Ageing and Retirement in Europe | n=10,446 | M=66.0 SD=9.7 50–101 |
52.1% | According to asymmetric fixed-effects regression, the onset of obesity was associated with a decrease of loneliness among men (ß=−.31, p<0.05) and an increase among women (ß=0.33, p<0.01). |
| Hajek (2020b)16 | Germany | BMI > 30 kg/m2 | Lubben Social Network Scale (six items) | longitudinal (two waves, 2014/2015 to 2015/2016, 20 months) | Study on Needs, Health Service Use, Costs and Health-Related Quality of Life in a Large Sample of Oldest-Old Primary Care Patients (85+) (AgeQualiDe) | n=675 | M=89.6 SD=2.8 85–100 |
67.9% | Random-effects logistic regression stated that social isolation was not associated with obesity. |
| Hajek (2018)21 | Germany | BMI > 30 kg/m2 | scale generated by Bude and Lantermann (four items) | cross-sectional | German Ageing Survey | n=7838 | M=64.4 SD=11.2 range not specified |
51.0% | As linear regression revealed, obesity was related to social exclusion only among women (ß=−0.1, p<0.05). |
| Hajek (2019)8 | Germany | BMI > 30 kg/m2 | Loneliness scale developed by Gierveld and van Tilburg (six items) | Longitudinal (four waves, 2002–2014) | German Ageing Survey | n=21,099 | M=63.4 SD=11.5 range not specified |
49.2% | Regarding fixed-effects regression, obesity was positively associated with loneliness among men (ß=0.1, p<0.05), but not among women. |
| Rotenberg (2017)18 | United Kingdom | BMI > 30 kg/m2 | UCLA-R Loneliness Scale (20 items) | Cross-sectional | Undergraduates from a mid-size university | n=137 | M=21.8 SD=4.7 18–57 |
58.4% | An ANOVA revealed that obesity was associated with increased levels of loneliness (p<0.001). |
| Sarlio-Lähteenkorva (1999)19 | Finland | BMI > 30 kg/m2 | Feeling lonely (dichotomous) | Cross-sectional | Survey of Living Conditions | n=6,016 | M=44.2 SD not specified 15–65 |
45% | With regard to logistic regression, feeling lonely was not associated with obesity. |
Notes: Hajek (2020a):17 adjusting for age, marital status, income, self-rated health, functional impairment, depressive symptoms and chronic diseases. Hajek (2020b):16 adjusting for age, gender, education, marital status, visual impairment, hearing impairment, dementia, depression and chronic diseases. Hajek (2018):21 adjusting for age, family status, monthly net equivalent income, smoking status, alcohol consumption, frequency of sports activities, self-rated health and chronic diseases. Hajek (2019):8 adjusting for age, employment status, family status, frequency of sports activities, depressive symptoms, and number of chronic diseases. Rotenberg (2017):18 no further adjustments Sarlio-Lähteenkorva (1999):19 adjusting for employment status, income, marital status and close friends.