We prospectively assessed the (1) frequency and socio-economic correlates of takeaway food consumption during adolescence; and (2) association between frequent takeaway food consumption with intakes of major food groups and anthropometric measures and blood pressure (BP). In total, 699 Sydney schoolchildren (380 girls and 319 boys) who had dietary data at both 12 and 17 years of age were included for analyses. Takeaway food consumption was self-reported and based on a single question. Anthropometric measures and BP were collected. The proportion of participants who ate takeaway foods once per week or more increased significantly over 5 years from the age of 12 to 17 years: 35·5–44·1 % (P<0·0001). In total, 12-year-old girls compared with boys had reduced odds of takeaway foods once per week or more at the age of 17 years (P=0·01), multivariable-adjusted OR 0·63 (95 % CI 0·44, 0·90). In total, 12-year-old children who ate takeaway foods once per week or more had significantly lower mean fruit (220·3 v. 253·0 g/d; P=0·03) and vegetable consumption (213·2 v. 247·7 g/d; P=0·004), 5 years later (at 17 years of age). Frequent takeaway food consumption at the age of 12 years was not associated with anthropometric indices and BP at the age of 17 years. Consumption of takeaway foods became more frequent during adolescence, particularly among boys, and it was associated with reduced intake of fruits and vegetables.