Dietary fat and sugar have been implicated in the rising obesity prevalence in the US. We determined trends of dietary total and added sugar intake of individuals over the past three decades by using NHANES I (1971-1975; n=20,175) and NHANES III (1988-1994; n=28,663). Codes of food reported consumption in NHANES I (n=1,823) were matched with those of NHANES III (n=4,723), based on total and added sugar contents primarily and then on similarity of other composition of each food. Matched food codes between two surveys were validated by a lack of differences in mean population food intake data analyzed by the original food codes vs by the matched codes for NHANES I for total intake of food and beverages (2070 vs. 2070 g/d), energy (1988 vs. 2000 Kcal/d), carbohydrates (224 vs. 236 g/d), % energy intake from fat (36 vs. 36 %) and other macro- and micronutrients. The mean dietary intake of all population increased from NHANES I to III for energy (7%,), total sugar (8%), added sugar (12%), total carbohydrate intake (18%), dietary fiber (19%) and total food and beverage intake (11%), while % energy from fat and protein intake decreased (7%, 1%, resp.). Directions and magnitudes of changes differ for each nutrient and subpopulation group. The increases in total and added sugar intake in the past three decades were more apparent in the diets of adults (19+ y; 14%, 18%, resp.) than those of children (1-18y; 0.5% and 5%, respectively).