Association of informal caregiving with body mass index and frequency of sporting activities: evidence of a population-based study in Germany

BACKGROUND: While most studies focused solely on the comparison between informal caregivers and non-caregivers, little is known about the relation between caregiving time or caregiving activities and lifestyle factors. Thus, the aim of this study was to examine whether informal caregiving time and type of caregiving activities are associated with body mass index (BMI) and the frequency of sporting activities among informal caregivers. METHODS: Cross-sectional data were gathered from the German Ageing Survey, a nationally representative study among community-dwelling individuals aged ≥40 that includes a total of n = 1380 people who provide informal care services. Self-reported BMI and self-reported frequency of sporting activities (daily; several times a week; once a week; 1-3 times a month; less often; never) were used as dependent variables. The average time of providing informal care per week as well as four different caregiving activities (help around the house; looking after someone; performing nursing care services; help in another way) were included as independent variables. Multiple ordinal and linear regressions were used to estimate the association between caregiving factors and the frequency of sporting activities and BMI, respectively. RESULTS: Among the 1380 informal caregivers, 65% provided help around the house, 83% looked after people, 28% provided nursing care services, and 68% provided any other help. Bivariate analyses showed that sporting activities and BMI differed by status of providing nursing care services, whereas the other three types of informal caregiving were not associated with BMI nor frequency of sporting activities except for the latter and provision of help around the house. Multiple regressions showed that BMI increased with caregiving time and performing nursing care services, whereas it was not associated with the other three caregiving activities. Likewise, the frequency of sporting activities decreased only with caregiving time and performing nursing care services. CONCLUSIONS: The present study revealed that caregiving time and performing nursing care services are associated with a higher BMI and a decreased frequency of sporting activities. As both, a higher BMI and fewer sporting activities are in turn related to various adverse health outcomes, this knowledge should be taken into account when planning informal caregiving. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12889-017-4786-6) contains supplementary material, which is available to authorized users.