Television viewing time and weight gain in colorectal cancer survivors: a prospective population-based study

Objective To investigate the prospective relationships between television viewing time and weight gain in the 3 years following colorectal cancer diagnosis for 1,867 colorectal cancer survivors (body mass index (BMI) >= 18.5 kg/m(2)). Methods BMI, television viewing time, physical activity, and socio-demographic and clinical covariates were assessed at baseline (5 months), 24 months and 36 months post-diagnosis. Multiple linear regression was used to study independent associations between baseline television viewing time and BMI at 24 and 36 months post-diagnosis. Results At both follow-up time points, there was a significant increase in mean BMI for participants reporting >= 5 h/day of television viewing compared to those watching < 3 h/day at baseline (24 months: 0.72 kg/m(2) (0.31, 1.12), p < 0.001; 36 months: 0.61 kg/m(2) (0.14, 1.07), p = 0.01), independent of baseline BMI, gender, age, education, marital status, smoking, cancer site, cancer disease stage, treatment mode and co-morbidities. Additional adjustment for baseline physical activity did not change results. Conclusions These findings suggest that a greater emphasis on decreasing television viewing time could help reduce weight gain among colorectal cancer survivors. This, in turn, could contribute to a risk reduction for co-morbid conditions such as type 2 diabetes and cardiovascular disease.