To describe the differences in socio-economic characteristics and body measurements between low, adequate and high energy reporting (LER, AER and HER) teenagers; furthermore, to investigate the relationship to misreporting mothers.

Cross-sectional study. Habitual dietary intake was reported in a questionnaire. Classification into LER, AER and HER using the Goldberg equation within three activity groups based on physical activity questionnaire and calculated BMR.

Stockholm, Sweden.

Four hundred and forty-one 16–17-year-old teenagers (57 % girls) and their mothers.

Of the teenagers, 17–19 % were classified as HER, while 13–16 % as LER. There was a highly significant trend from HER to LER in BMI (P < 0·001) and body fat % (P < 0·001). There was also a trend in number of working hours of mother (P = 0·01), family income (P = 0·008) and number of siblings (among boys only) (P = 0·02), but not in educational level of either father or mother. HER teenagers were lean, had mothers working fewer hours with lower income and had siblings. It was more likely that an LER girl had an LER mother than an AER mother (OR = 3·32; P = 0·002).

The reasons for the high number of over-reporters could be many: misclassification due to growth, lacking established eating pattern due to young age or method-specific. Nevertheless, the inverted characteristic of HER compared to LER indicates that this is a specific group, worth further investigation.

To study associations between reported sugar intake and salivary bacteria (mutans streptococci, MS and lactobacilli, LB), and sugar intake in relation to body mass index (BMI), in women and adolescents.

Cross-sectional study. Habitual dietary intake was reported in a questionnaire and whole saliva samples were collected and cultivated.

Stockholm, Sweden.

Four hundred and fourteen mothers and their 16-year-old children (57% girls).

Reported total sugar intake was significantly associated with LB in mothers (P = 0.001), but not in daughters and sons (P = 0.03 for mother–son interaction). When excluding lactose, the associations with LB and MS were significant in daughters (P = 0.032 and 0.005, respectively). High BMI and sugar intake from milk were independently associated with MS counts in mothers in a multiple regression model (R2 = 0.053). In daughters, sugar from beverages, candies/chocolates and fruits were all independently associated with MS counts (R2 = 0.074), whereas in sons, only mothers’ MS counts were associated (R2 = 0.084). High BMI, low intake from cooked meals and high intake of candies/chocolates were all independently associated with LB in mothers (R2 = 0.076), while, except for candies/chocolates in daughters, no significant associations were found in children. BMI was significantly associated with bacteria counts in both mothers and children, whereas reported sugar intake was not.

The associations between reported sugar intake and bacteria were generally weak. In mothers and daughters, some significant associations were found, but not in sons. Bacteria counts, but not reported sugar intake, were positively associated with BMI.