Relações sociais, atividade física de lazer e obesidade: evidências longitudinais

Abstract

The influences of social relations in health is being widely investigated in different contexts. Regarding the influence of social relationships in leisure-time physical activity (LTPA) and obesity, longitudinal multidimensional approaches are scarce. The first paper aim to investigate how four dimensions of social support affect LTPA engagement, maintenance, type, and time spent by adults during a two-year follow-up (1999-2001). While the second paper aim to investigate the effect of five social relationships indicators on obesity and the potential sex differences in associations after nine years of follow-up (1991-2000). For the first paper were analysed a longitudinal data from 3,253 non-faculty public employees at a university in Rio de Janeiro (the Pró-Saúde study). While for the second paper, longitudinal data from the Swedish level of living Survey (LNU) were used. Results from the first paper found statistically significant associations (p<0.05) between dimensions of social support and group LTPA were found in the engagement group. Also, the emotional/information dimension was associated with time spent on LTPA (OR=2.01; 95% CI 1.2-3.9). In the maintenance group, material support was associated with group LTPA (OR=1.80; 95% CI; 1.1-3.1) and the positive social interaction dimension was associated with time spent on LTPA (OR=1.65; 95% CI; 1.1-2.7). Results from the second paper showed that after adjustment for confounders, lack of emotional support (RR=1.98; 95% CI, 1.1-4.6) influence the incidence of obesity among men. In addition, men with the lowest level of SRI (social relationships index) had an increased risk of being obese (RR=2.22; 95% CI, 1.1-4.4). Among women SRI was not significantly associated with obesity. However, a protective effect on obesity for women who changed their marital status from married to unmarried (RR=0.39; 95% CI, 0.2-0.9) was found. Regarding the first paper, all dimensions of social support influenced LTPA type or the time spent on the activity. However, our findings suggest that social support is more important in engagement than in maintenance. This finding is important, because it suggests that maintenance of LTPA must be associated with other factors beyond the individual s level of social support, such as a suitable environment and social/health policies directed towards the practice of LTPA. In relation to the second paper, the present study provides evidence of an inverse association between social relationships and the incidence of obesity, highlighting sex differences. Moreover, it was suggested that body image concerns among women could be an explanation for sex differences.