The aim was to describe the energy intake and composition of the diet of 1200 9-, 12-, 15-, 18-, 21- and 24-year-old Finns in 1986 and changes in their diet from 1980 to 1986. Data on food consumption were collected using the 48 h recall method. In 1980 protein accounted for 14%, fat for 38% and carbohydrates for 48% of total energy intake, and in 1986 for 15%, 38% and 47%, respectively. The mean P/S ratio increased from 0.24 to 0.31 while the regional differences in the intakes of fatty acids remained unchanged, the P/S ratio being higher in urban than in rural areas and higher in western than in eastern Finland. In 1986 the diet of 15-, 18- and 24-year-old males contained more fat, saturated fatty acids and monounsaturated fatty acids but less sucrose than that of females. The difference in the diet between young men and women, if continued, might increase the male/female ratio at risk for coronary heart disease, which is already pronounced in Finland.