Trends in energy and macronutrient intakes, body weight and physical activity in female university students (1988–2003), and effects of excluding under-reporters

Abstract

The present study investigated trends in reported energy intake, macronutrient intake, physical activity level (PAL) and body weight and effects of excluding under-reporters (UR). Dietary intake and time spent in sixteen activity categories were recorded by 887 female university students (median age 29 years) from 1988 to 2003. Energy expenditure (EE) and PAL were measured using a factorial method. All data collected were self-reported. Individuals with reported EI:EE<0·76 were classified as UR. The remainder were classified as non-under-reporters (NUR). Trends were determined from simple linear regression of median data for each year for the entire cohort (ALL) and for NUR and UR separately, and from multiple regression analysis with the subgroups (NUR and UR) as an additional predictor (BOTH). Prevalence of under-reporting and overweight increased between 1988 and 2003. In ALL and BOTH there were trends to increased body mass, protein intake (g/d and % energy) and carbohydrate intake (% energy only) and decreased fat and alcohol intakes (g/d and % energy). In BOTH there were also increases in reported EI and carbohydrate intake (g/d). None of the trends in NUR was significantly different from those in UR, but some trends in ALL and/or BOTH were not significant when UR were excluded. Trends remaining significant in NUR were increased reported energy intake, protein (g/d) and carbohydrate (g/d) intakes, and decreased fat (% energy only) intake. There were no significant trends in PAL. We conclude that some, but not all, dietary trends were affected by exclusion of UR.