Few studies have examined nutrition transition in children in China. Our aim, in the present study, was to examine temporal trends in dietary energy, fat, carbohydrate and protein intake in Chinese children aged 7–17 years. The analysis used individual level, consecutive 3 d dietary recall data from seven rounds of the China Health and Nutrition Surveys in 1991 (n 2714), 1993 (n 2542), 1997 (n 2516), 2000 (n 2142), 2004 (n 1341), 2006 (n 1072) and 2009 (n 996). Mixed-effect models were constructed to obtain adjusted means and to examine trends after adjusting for intra-class correlation within clusters and for covariates including age, sex, urban/rural residence and income. From 1991 to 2009, daily energy intake steadily declined from 9511·0 to 7658·2 kJ (P < 0·0001). There was a steady decline in daily carbohydrate intake from 382·5 to 254·1 g (P < 0·0001), and in the proportion of energy from carbohydrate from 66·7 to 56·8 % (P < 0·0001). In contrast, daily fat intake steadily increased from 54·8 to 66·0 g (P < 0·0001), as did the proportion of energy from fat from 21·5 to 30·0 % (P < 0·0001). The proportion of children who consumed a diet with more than 30 % of energy from fat increased from 20·1 to 49·4 % (P < 0·0001). The proportion of energy from protein increased from 11·8 to 13·1 % (P < 0·0001), although daily protein intake dropped from 66·2 to 58·0 g (P < 0·0001). Our data suggest that Chinese children have been undergoing a rapid nutrition transition to a high-fat diet.