Television viewing and obesity: A prospective study in the 1958 British birth cohort

Objective:To assess whether frequency of television viewing in adolescence (11 and 16 years) or early adulthood (23 years) affected subsequent changes in body mass index (BMI) through to mid-adulthood life, and waist-hip ratio in mid-adulthood. Subjects: The 1958 British birth cohort includes all births in 1 week in March 1958 in England, Scotland and Wales. The main analyses included at least 11301 participants. Outcome measures included BMI at 16, 23, 33 and 45 years and waist-hip ratio at 45 years. Results: Watching television 'often' at 16 years (but not 11 years) was associated with a faster gain in BMI between 16 and 45 years in males (0.011 kg m^-2 per year, 95% confidence interval (CI) 0.003, 0.019) and females (0.013 kg m^-2 per year, 95%CI 0.003, 0.023). More frequent television viewing at 11, 16 and 23 years was associated with a faster gain in BMI between 23 and 45 years in females, but not in males. Television viewing at 23 years was associated with waist-hip ratio at 45 years: participants watching ≤5 times per week had a waist-hip ratio 0.01 higher than those watching less often. At 45 years, those watching television for ≤4 h day^-1 had a waist-hip ratio 0.03-0.04 higher than those watching for <1 h day^-1 Conclusions: More frequent television viewing in adolescence and early adulthood is associated with greater BMI gains through to mid-adulthood and with central adiposity in mid-life. Television viewing may be a useful behaviour to target in strategies to prevent obesity.