Lars-Eric Bratteby

Food habits and energy and nutrient intake in Swedish adolescents approaching the year 2000.

In 1993‐94 a nutritional survey of 15‐year‐old adolescents was carried out in Uppsala, a university city in eastern Sweden, and in Trollhättan, an industrial town in the western part of the country. The study was the beginning of a longitudinal nutritional survey of 193 boys and 218 girls randomly selected from the official population register. The dietary methods used were a food frequency questionnaire (FFQ) and a combined estimated and weighed 7‐day dietary record. According to the FFQ both boys and girls consumed cereals, butter or margarine and something from the group meat/fish/eggs every day. Milk, milk products, sweets and snacks were consumed more than once per day. Vegetables and fruit/ roots were consumed less often. There was relatively good correlation between the FFQ and the 7‐day record results.

Relationships between trace element concentrations in human blood and serum

Trace element interactions can affect the absorption, metabolism, or effects of elements. Also, different elements may derive from the same source. Associations in biological media between element concentrations may indicate such phenomena. A large number of correlations were found between 13 trace elements (Co, Cu, Zn, Se, Rb, Rh, Pd, Cd, W, Pt, Hg, Tl, and Pb) in human blood and/or serum, as investigated in 372 Swedish adolescents. Notably, serum Se correlated with blood Pb and blood Hg and Cu and Zn were correlated to each other in both blood and serum. The elements Pt, Pd and Rh, spread in the environment through use of catalytic converters in cars, were closely correlated in both blood and serum. Apart from the correlations with a probable biological or exposure-related explanation, several other correlations, of yet unknown importance and origin, were found.

Physical Activity in Relation to Energy Intake and Body Fat in 8‐ and 13‐Year‐Old Children in Sweden

ABSTRACT. A random sample of 682 8‐ and 13‐year‐old children resident in Sweden was studied with regard to physical activity, energy intake, height, weight and skinfold thickness. A reduction of physical activity over the years was indicated by a tendency towards a higher body fat content in spite of a lower mean energy intake as compared with such values obtained 10‐15 years ago in Swedish children of equal ages. Children characterized by high habitual physical activity tended to have a lower body fat content, despite a higher energy intake, than less active children. Children, especially girls, of parents with a low educational level showed a tendency towards higher body fat content as compared with those of parents with higher education.

Dietary iron intake and iron status in adolescents

The aim of this study was to evaluate the dietary iron intake of 15‐year‐old adolescents from two different regions of Sweden, in relation to their iron status. The study comprised 185 boys and 209 girls, randomly selected from the official population register. The iron intake was calculated from a 7‐day record, and varied between 7 and 35 and 6 and 27 mg per day for boys and girls, respectively. The daily median intakes in boys and girls were 18.7 and 14.2 mg, respectively. S‐ferritin, s‐iron, and s‐transferrin saturation, measured in all the subjects, did not differ significantly between the two regions. However, the mean serum ferritin concentration was significantly higher in the boys (36.4μgl‐1) than in the girls (29.4μgl‐1)(p < 0.001). Low s‐ferritin levels, defined as s‐ferritin < 12 μgl‐1 were found in seven boys (3.7%) and in 29 girls (13.9%). None of the adolescents had iron deficiency anaemia, defined as Hb< 110gl‐1 in combination with s‐ferritin < 12μgl‐1. Regression and correlation analyses did not show any significant correlation between dietary iron intake and s‐ferritin, or between s‐ferritin and haemoglobin (Hb), MCH and MCHC. A significant correlation was found, however, between s‐ferritin and transferrin saturation (p < 0.005) in both sexes. When the adolescents who still had s‐ferritin < 12μgl‐1 at a second blood examination were given a 6 weeks trial with oral iron therapy, all of them showed an increase both in s‐ferritin and in blood Hb. The 95% confidence intervals of s‐ferritin for 15‐year‐old Swedish boys and girls were defined as 11‐90 and 7 85 μ.gl‐1, respectively.

Physical Activity and Sports Involvement in 8‐ and 13‐Year‐Old Children in Sweden

ABSTRACT. The physical activity of randomly selected 8‐ and 13‐year‐old children, living in four different regions of Sweden, was investigated by means of a questionnaire. The younger children of each sex were found to be physically more active than the older ones, and within each age group the boys were physically more active than the girls. The results points to higher sports involvement today compared with 10–15 years ago, especially among younger children. It was also shown that regular physical training constituted a smaller proportion of the total physical activity among the younger children than among the older ones. At both ages and in both sexes the rate of regular physical training was lower in municipalities of less than 1000 inhabitants, and in the 8‐year‐old children it was also lower in municipalities of less than 5 000 inhabitants. Among the girls regular physical training was more common in those whose fathers had a high educational level compared with the girls who had fathers of a lower educational level.

Muscle strength correlates with total body bone mineral density in young women but not in men

Background: Osteoporosis is a growing health problem. One of the proposed reasons for this is a more sedentary lifestyle. The aim of this study was to investigate the associations between muscle strength and total body bone mineral density (TBMD) in young adults at expected peak bone mass.

Body composition in a cohort of Swedish adolescents aged 15, 17 and 20.5 years.

Objective: To assess variables of body composition and identify their correlates in a group of individuals studied from adolescence to early adulthood.

Physical activity, energy expenditure and their correlates in two cohorts of Swedish subjects between adolescence and early adulthood

Objective:To assess physical activity and energy expenditure and to identify their correlates during adolescence and early adulthood.Design:In a cohort study, total energy expenditure (TEE) and physical activity level (PAL) were assessed at 15 and 21 y from a 7-day activity diary and predicted BMR. The influences on TEE and PAL of body size, gender, sexual maturity, physical activity habits, sitting time, region, social conditions, employment, food habits, smoking and alcohol intake were examined in multivariate analyses.Subjects:71 male and 89 female subjects, living in two socioeconomically different regions of Sweden, a university region and an industrial region.Setting:The university city of Uppsala and the industrial town of Trollhättan.Results:At both 15 and 21 y, PAL and TEE were high, with gender, sitting time and physical activity habits as main correlates. At age 21 y, employment and the mothers educational level also appeared as significant correlates. The relations between the main variables and their correlates were more complex than at age 15 y, and the sitting time was reduced and the activity habits were changed.Conclusions:A reduction of daily sitting appears to be a major reason why high levels of physical activity and energy expenditure were maintained from 15 to 21 y of age in spite of changed and less frequent activity habits during this interval.Sponsorship:Uppsala University, County Councils of Uppsala and Älvsborg and the Swedish Dairies Association of Research and Development.

Whole-body mineral measurements in Swedish adolescents at 17 years compared to 15 years of age

Aim: To provide reference data for bone mineral variables in 15‐ and 17‐y‐old adolescents and to analyse the relationships between these variables and measures of bone and body size, gender, puberty, growth, various lifestyle and environmental factors and socioeconomic background. Methods: In the same 321 randomly selected adolescents (147 boys and 174 girls) living in two different regions of Sweden, the total bone mineral content (TBMC), bone area (BA) and total bone mineral density (TBMD) were assessed by dual‐energy X‐ray absorptiometry at ages 15 and 17 y. The effects of bone and body size, gender, growth, sexual maturity, physical activity, region of domicile, social conditions, food habits, smoking and alcohol intake on TBMC and TBMD were examined in multivariate analyses. Results: In the 15‐y‐old adolescents, BA, height, gender, physical activity, maturity and weight explained 91% and 48%, of the variance in TBMC and TBMD, respectively. In similar analyses in the 17‐y‐olds, the corresponding figures were 92% and 62%, respectively, when BA, height, growth, physical activity, gender and region emerged as significant in the model. In all these analyses, BA explained most of the variance in TBMC and TBMD. No significant reduction of variance was found when different measures of social conditions, smoking, food habits, alcohol or dietary intakes of energy, calcium or vitamin D were included in the models. The reason why region of domicile had a significant impact on TBMC in the 17‐y‐olds is not known. The fact that the normal fluoride concentration in drinking water (1.1 mg/L) is 10 times higher in the region where TBMC was higher than in the other region is an interesting observation.

Serum ferritin and transferrin receptor concentrations during the transition from adolescence to adulthood in a healthy Swedish population.

Aim:As part of a longitudinal nutrition study of adolescents, changes in serum ferritin (s‐Ft), serum transferrin receptors (s‐TfR) and the TfR/Ft ratio from 15 to 21 y of age were studied in randomly selected Swedish adolescents. Methods:Blood samples from 60 males and 66 females were drawn at 15, 17 and 21 y of age. Results:In males, median s‐Ft increased significantly from 33 (μg 1 −1 at 15 y to 96 (μg 1−1 at 21 y, and in females, after a non‐significant decrease at 17 y, from 27 at 15 y to 34 (μg 1 at 21 y. Between 15 and 17 y, s‐TfR increased significantly, in males from 5.9 to 7.7 p.g 1, and in females from 5.2 to 7.6 μg 1−1, whereas s‐TfR decreased significantly in both genders between 17 and 21 y. The log (TfR/Ft) ratio did not change in males between 15 and 17 y, but decreased significantly from 2.2 ± 0.3 to 1.8 ±0.3 by the age of 21 y. In females, the TfR/Ft ratio increased significantly between 15 and 17 y, whereas a significant decrease was found by the age of 21 y. S‐Ft <12 μg 1−1 at 15, 17 and 21 y was 3, 2 and 2% in males, and in females 18, 26 and 21%, respectively.