Response to letters regarding article, "television viewing time and mortality: The Australian diabetes, obesity and lifestyle study (AusDiab)" - Dunstan, D.; Barr, E.; Shaw, J.; Magliano, D.; Zimmet, P.; Salmon, J.; Cameron, A.; Owen, N.; Healy, Genevieve; Balkau, B. (Lippincott Williams & Wilkins, 2010)