Gösta Samuelson

A 7-day activity diary for assessment of daily energy expenditure validated by the doubly labelled water method in adolescents

Objectives: To validate the use of an activity diary and predicted BMR for assessment of daily total energy expenditure (TEE) and physical activity level (PAL=TEE/BMR) in adolescents. Design: TEE and PAL estimated from activity diary records kept for seven days and BMR predicted from age, gender and body weight were compared with the results of doubly labelled water (DLW) measurements and indirect calorimetry performed during the same time period. Setting: The Unit of Paediatric Physiology of the Department of Clinical Physiology, University Hospital, Uppsala, Sweden. Subjects: Fifty randomly selected 15 y old adolescents (25 boys and 25 girls). Results: The mean difference between TEE estimated in all adolescents by the activity diary and by DLW methods was +1.2%. The limits of agreement (mean difference ±2 s.d.) were −3.47 and +3.77 MJ/d, equivalent to a coefficient of variation of 15%. The mean difference between PAL assessed by activity diary records and by DLW measurements was +0.001, and the limits of agreement between the two methods were ±0.54. Conclusions: The results imply that the activity diary method provides a close estimate of TEE and PAL in population groups. Sponsorship: The Swedish Medical Research Council (Project no. 10379), Uppsala University, and the University Hospital of Uppsala.

The Copenhagen cohort study on infant nutrition and growth: duration of breast feeding and influencing factors

Michaelsen KF, Larsen PS, Thomsen BL, Samuelson G. The Copenhagen cohort study on infant nutrition and growth: duration of breast feeding and influencing factors. Acta Pædiatr 1994;83:565–71. Stockholm. ISSN 0803–5253

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.

A longitudinal study of iron status in healthy Danish infants: effects of early iron status, growth velocity and dietary factors

In a cohort of term infants (n=91), followed from birth to 12 months, iron intake was examined by 24-h food records, and iron status by blood samples (haemoglobin (Hb)), mean corpuscular volume (MCV), serum values for iron, ferritin and transferrin, and erythrocyte protoporphyrin) at 2, 6 and 9 months. At 9 months of age, 5% had anaemia (Hb<105 g/l), but none had developed iron deficiency according to strict definitions used in this study (serum ferritin < 13 micrograms/l and transferrin saturation < 10%). Infants with high serum ferritin, serum transferrin and erythrocyte protoporphyrin values at one blood sampling also had high values at the following sample (tracking, r=0.45-0.80), suggesting that iron stores at delivery are an important determinant of iron stores during late infancy. Factors related to changes in serum ferritin were investigated by multiple linear regression. From 2 to 6 months, serum ferritin was negatively associated with knee-heel growth velocity (p=0.006) and positively with intake of infant formula (p=0.04). From 6 to 9 months it was negatively associated with intake of bread (p=0.001), and there was a trend for a positive association with intake of meat (p=0.07) and fish (p=0.08) and for a negative association with intake of cows milk (p=0.07). In conclusion, those with a high growth velocity and a dietary pattern with a high intake of bread and a low intake of meat and fish had lower ferritin values and thereby an increased risk of depleting their iron stores later during infancy.

Changes in food habits in healthy Swedish adolescents during the transition from adolescence to adulthood

Objective: To investigate the change in food habits in Swedish adolescents between 15 and 21 y of age with reference to age, sex, region and socioeconomic background.Design: A longitudinal study from 1993 to 1999.Setting: Two different regions in Sweden, the university city of Uppsala and the industrial town of Trollhättan.Subjects: On three different occasions, 1993, 1995 and 1999, 208 adolescents, 96 males and 112 females, were studied.Methods: A food frequency questionnaire containing 29 different food groups was used. The questionnaire also contained questions about food habits and amounts of some food items and socioeconomic conditions of the participants and their families.Results: At 17 and 21 y of age, the adolescents consumed significantly more often pasta, vegetables, coffee and tea compared to age 15, while the frequency consumption of fat spread, milk, bread, potatoes, carrots and buns and biscuits decreased. The changes between 15 and 17 were smaller than between age 17 and 21. At age 21, the males decreased their intake of fruit, while the females decreased their intake of meat. No-meat consumers among females increased from 2 to 13%. Higher educational level of the mothers of the adolescents was associated with more frequent consumption of vegetables and pasta between ages 17 and 21. Milk consumption decreased significantly in both sexes. Breakfast habits did not change: 90% had breakfast five times/week or more.Conclusions: Food habits change significantly during adolescence along with lifestyle changes. Therefore, health promotion during adolescence ought to be more supported by the society.Sponsorship: County Councils of Uppsala and Älvsborg and the Dairies Association of Research and Development.

An Epidemiological Study of Child Health and Nutrition in a Northern Swedish County

The aim of the study was to investigate the accuracy of children’s reports of their consumption of a school meal. Nutritional intake from the school lunch was studied for 56 healthy 8-year-olds and 43

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.

Zinc intake, zinc status and growth in a longitudinal study of healthy Danish infants

Mild, growth‐limiting zinc deficiency might be prevalent in otherwise healthy infants according to recent studies. We examined zinc intake and status in 91 healthy term infants from birth to 12 months, as part of the Copenhagen Cohort Study on Infant Nutrition and Growth. Zinc intake was recorded monthly and the amount of zinc absorbed was estimated. These estimates were below recently published FAO/WHO/IAEA values for basal requirements in 68%, 62% and 14% of the infants at 2, 4 and 9 months of age, respectively. Serum zinc decreased significantly (p < 0.01) from 10.6 μmol/l at 6 months to 8.4μmol/l at 9 months of age (normal range 10–18 μmol/l). Erythrocyte metallothionein values, a tentative indicator of long‐term zinc status, decreased significantly from 2 to 6 months (p < 0.001) and from 6 to 9 months (p < 0.01). Serum zinc at 9 months was positively associated with growth velocity during the period from 6 to 9 months (weight: p = 0.05; knee‐heel length: p = 0.002). The results provide descriptive data on zinc intake and zinc status in healthy Danish infants. Although some of our data suggest suboptimal zinc status during late infancy, evidence for this can only be obtained through a randomized intervention study.

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.

Daily energy expenditure and physical activity assessed by an activity diary in 374 randomly selected 15-year-old adolescents.

Objectives: To assess the average daily levels of physical activity, energy expenditure and the time and energy spent at different activities in two cohorts of Swedish adolescents. Design: Total energy expenditure (TEE) and physical activity level (PAL=TEE/basal metabolic rate (BMR)) were estimated in 374 randomly selected healthy adolescents living in two different regions of Sweden on the basis of a seven-day activity diary (AD) and predicted BMR. A validation of the estimates from the AD with the doubly labelled water (DLW) method in a randomly selected subsample of 50 of these subjects is presented elsewhere. Setting: The Unit of Paediatric Physiology of the Department of Clinical Physiology, University Hospital, Uppsala and the Department of Paediatrics, Northern Älvsborg Hospital, Trollhättan, Sweden. Results: No significant differences in TEE and PAL were found between the adolescents of the two regions. High levels of TEE (14.2 and 10.9 MJ/d in boys and girls, respectively) and PAL (1.95 and 1.80) were observed. There was a close association between the PAL of the adolescents and their reported time spent sitting. Those with the lowest PAL values spent 3–6 h longer each day sitting compared to those with the highest PAL values. The results also indicate that everyday activities such as walking and bicycling have a crucial impact on the PAL values. Conclusions: In the 15 y old adolescents of the two studied regions of Sweden, high and concordant levels of energy expenditure and physical activity were found. Sponsorship: Swedish Medical Research Council (project no. 10379), Uppsala University, and the County Councils of Uppsala and Trollhättan.