As part of the 16–17 year follow-up of the 1970 longitudinal birth cohort study, The International Centre for Child Studies collected dietary data from a National sample of 4760 teenagers. Dietary intake data were collected in 4 d unweighed dietary diaries, distributed by schools and returned by post. Dietary intake data were quantitatively coded, and the intakes of energy, macronutrients and non-starch polysaccharides (NSP) are reported. Intakes of fat and extrinsic sugars, expressed as a percentage of energy intake, exceeded recent recommendations (Department of Health, 1991), and the intakes of intrinsic sugars, milk sugars and starch, and NSP were considerably lower than recommended. Only 25 % of males and 10 % of females achieved intakes of 18 g NSP/d. The main food groups contributing fat (%) to the diets of teenagers (for males and females respectively) were meat and meat products (24·2, 22·1). Spreading fats (18·6, 18·1) and cereals and cereal products (18, 17·8), whilst the major sources of sugars (%) were (for males and females respectively) sugar and confectionary (28·2, 26·4), cereals and cereal products (24·5, 23) and beverages (21·9, 21·5). Less than half the cohort drank alcohol during the recording period, and about 6% of females drank more than 2 units alcohol/d, and about 6% of males drank more than 3 units alcohol/d.