Colette Montgomery

Fundamental movement skills and habitual physical activity in young children.

PURPOSE To test for relationships between objectively measured habitual physical activity and fundamental movement skills in a relatively large and representative sample of preschool children. METHODS Physical activity was measured over 6 d using the Computer Science and Applications (CSA) accelerometer in 394 boys and girls (mean age 4.2, SD 0.5 yr). Children were scored on 15 fundamental movement skills, based on the Movement Assessment Battery, by a single observer. RESULTS Total physical activity (r=0.10, P<0.05) and percent time spent in moderate to vigorous physical activity (MVPA) (r=0.18, P<0.001) were significantly correlated with total movement skills score. Time spent in light-intensity physical activity was not significantly correlated with motor skills score (r=0.02, P>0.05). CONCLUSIONS In this sample and setting, fundamental movement skills were significantly associated with habitual physical activity, but the association between the two variables was weak. The present study questions whether the widely assumed relationships between motor skills and habitual physical activity actually exist in young children.

Total energy expenditure and physical activity in young Scottish children: mixed longitudinal study

Childhood obesity has been attributed to a decline in total energy expenditure (TEE). We measured TEE, physical activity, and sedentary behaviour in a representative sample of young children from Glasgow, UK, at age 3 years (n=78), and we did a follow-up study at age 5 years (n=72). Mean physical activity level (TEE/resting energy expenditure) was 1.56 (SD 0.39) at age 3 years and 1.61 (0.22) at age 5 years. Median time in sedentary behaviour was 79% of monitored hours at age 3 years (IQR 74-84) and 76% (71-80) at age 5 years. Median time spent in moderate to vigorous physical activity represented only 2% of monitored hours at age 3 years (IQR 1-4) and 4% at age 5 years (2-6). Modern British children establish a sedentary lifestyle at an early age.

Maternal docosahexaenoic acid supplementation during pregnancy and visual evoked potential development in term infants: a double blind, prospective, randomised trial

Aim: To test the hypothesis that maternal docosahexaenoic acid (DHA) supplementation during pregnancy enhances maturation of the visual evoked potential (VEP) in healthy term infants. Methods: One hundred women were supplemented with either fish oil capsules rich in DHA (n = 50) or placebo capsules (n = 50) from week 15 of pregnancy until delivery. Total fatty acids in red blood cells and plasma were measured at weeks 15, 28, and 40 of pregnancy and at delivery in umbilical cord blood. Infant visual pathway development was assessed using VEPs recorded to flash stimuli shortly after birth and to both flash and pattern-reversal stimuli at 50 and 66 weeks post-conceptional age (PCA). Results: Maternal supplementation did not significantly elevate the level of DHA in umbilical cord blood. Moreover, there were no significant differences in any of the VEP measures observed between supplementation groups. However, maturity of the pattern-reversal VEP at 50 and 66 weeks PCA was associated with DHA status of the infants at birth. Infants with higher DHA status, both as a concentration and as a percentage of total fatty acids, showed shorter P100 peak latencies of the pattern-reversal VEP than those with lower DHA status. Conclusions: Maternal DHA supplementation during pregnancy did not enhance VEP maturation in healthy term infants. However, these results show an association between the DHA status of infants at term and early postnatal development of the pattern-reversal VEP, suggesting that DHA status itself may influence maturation of the central visual pathways.

Effect of socioeconomic status on objectively measured physical activity

Background: A socioeconomic gradient in childhood obesity is known to be present by the age of school entry in the UK. The origin of this gradient is unclear at present, but must lie in socioeconomic differences in habitual physical activity, sedentary behaviour, or dietary intake. Aims: To test the hypothesis that habitual physical activity and/or sedentary behaviour are associated with socioeconomic status (SES) in young Scottish children. Methods: Observational study of 339 children (mean age 4.2 years, SD 0.3) in which habitual physical activity and sedentary behaviour were measured by accelerometry over six days (study 1). In a second study, 39 pairs of children of distinctly different SES (mean age 5.6 years, SD 0.3) were tested for differences in habitual physical activity and sedentary behaviour by accelerometry over seven days. Results: In study 1, SES was not a significant factor in explaining the amount of time spent in physical activity or sedentary behaviour once gender and month of measurement were taken into account. In study 2, there were no significant differences in time spent in physical activity or sedentary behaviour between affluent and deprived groups. Conclusion: Results do not support the hypothesis that low SES in young Scottish children is associated with lower habitual physical activity or higher engagement in sedentary behaviour.

Maternal docosahexaenoic acid supplementation and fetal accretion

Docosahexaenoic acid (DHA) (22 : 6n-3) is a polyunsaturated fatty acid that is an essential constituent of membranes, particularly of the nervous system. Infants acquire DHA from their mothers, either prenatally via the placenta or postnatally in milk. The present study aimed to test the hypothesis that maternal supplementation during the second and third trimesters of pregnancy enriches maternal and/or fetal DHA status. In a randomised, prospective, double-blind study 100 mothers received either fish-oil capsules containing 400 mg DHA/g (200 mg/d) (n 50), or placebo containing 810 mg oleic acid/g (400 mg/d) (n 50) from 15 weeks gestation until term. Venous blood samples were obtained from mothers at 15, 28 and 40 weeks, and from the umbilical cord at birth. Total fatty acids in plasma and erythrocytes were analysed by GC-MS. There were no significant differences between maternal groups in baseline DHA, as a proportion of total fatty acids (g/100 g total fatty acids) or concentration (nmol/ml), in plasma and erythrocytes. DHA concentrations in plasma at 28 weeks (P=0.02) and erythrocytes at both 28 weeks (P=0.03) and term (P=0.02) were 20 % higher in supplemented mothers than the placebo group. DHA accounted for a higher proportion of total fatty acids in erythrocytes of supplemented mothers at 28 weeks (P=0.003) and term (P=0.01). There were no significant differences between groups in DHA (g/100 g total fatty acids or nmol/l) in cord blood. Maternal DHA status was maximal in mid-trimester and declined to term, at a lower rate in supplemented compared with unsupplemented mothers. Maternal DHA supplementation significantly increases maternal DHA status and limits the last trimester decline in maternal status, aiding preferential transfer of DHA from mother to fetus.

Validation of energy intake by 24-hour multiple pass recall: comparison with total energy expenditure in children aged 5-7 years.

Accurate measurement of energy intake (EI) is essential in studies of energy balance in all age groups. Reported values for EI can be validated against total energy expenditure (TEE) measured using doubly labelled water (DLW). Our previous work has indicated that the use of the standardized 24 h multiple pass recall (24 h MPR) method produces slight overestimates of EI in pre-school children which are inaccurate at individual level but acceptable at group level. To extend this work, the current study validated EI by 24 h MPR against TEE by DLW in sixty-three (thirty-two boys) school-aged children (median age 6 years). In both boys and girls, reported EI was higher than TEE, although this difference was only significant in the girls (median difference 420 kJ/d, P=0.05). On analysis of agreement between TEE and EI, the group bias was an overestimation of EI by 250 kJ/d with wide limits of agreement (-2880, 2380 kJ/d). EI was over-reported relative to TEE by 7 % and 0.9 % in girls and boys, respectively. The bias in the current study was lower than in our previous study of pre-school children, suggesting that estimates of EI become less inaccurate as children age. However, the current study suggests that the 24 h MPR is inaccurate at the individual level.

Parental feeding style, energy intake and weight status in young Scottish children

Parental feeding style, as measured by the Child Feeding Questionnaire (CFQ), may be an important influence on child feeding behaviour and weight status in early to mid childhood, but more evidence on parental feeding style is required from samples outside the USA. We aimed to use the CFQ in a sample of 117 Scottish children (boys n 53, girls n 64 mean age 4.6 (SD 0.5) years) to: characterise gender differences and changes over time (in forty of the 117 children studied over 2 years); test associations between parental feeding style, free-living energy intake (measured over 3 days using the multiple pass 24-h recall), and weight status (BMI SD score). No dimensions of parental feeding style changed significantly over 2 years in the longitudinal study (P>0.05 in all cases). No aspects of parental feeding style as measured by the CFQ differed significantly between the sexes (P>0.05 in all cases). Parental perceptions of child weight status were generally significantly positively correlated with child weight status as measured by the BMI SD score. In this sample and setting, measures of parental control over child feeding were generally not associated with child energy intake or weight status.

Energy intake by multiple pass 24 h recall and total energy expenditure: a comparison in a representative sample of 3–4-year-olds

The accuracy of the multiple pass 24 h recall for assessment of habitual energy intake in pre-school children is unclear. The primary aim of this study was to assess its accuracy by comparison with measurement of total energy expenditure by doubly-labelled water in a representative sample of forty-one 3-4-year-olds. The recall method was well tolerated by subjects and was administered quickly and easily. However, it produced estimates of energy intake which significantly exceeded measures of total energy expenditure from doubly-labelled water, mean paired difference 660 kJ/d (P<0.01). Agreement between the two methods was poor at the individual level: limits of agreement 660+/-3018 kJ/d. Error and imprecision in both methods contribute to individual differences, but the present study suggests that the multiple pass 24 h recall does not provide accurate estimates of dietary energy intake in individual children.

Energy intake variability in free-living young children

It has been suggested that young children regulate their daily energy intake very closely with highly stable day-to-day total energy intake. This hypothesis was developed on the basis of an experimental study of 15 children aged 26 to 62 months, which reported a within-subject coefficient of variation (CV) in daily energy intake of 10.4%. We tested the hypothesis that free-living energy intakes were highly stable on a day-to-day basis in a sample of free-living young children from Glasgow, Scotland. In 101 children (47 boys) aged 2.6–6.8 years, energy intake was measured using multiple-pass 24-h recalls. Within-subject CV was 19.2%, which was significantly higher than the 10.4% reported by previously Birch and colleagues (p<0.0001). In addition, we identified four other studies on free-living children with within-subject CVs ranging from 16.1–28.7%. This evidence indicates that young children show a wide intra-individual variation in day-to-day regulation of energy intake in a free-living environment.

Fatty acid status of women of reproductive age

Objective: Healthy foetal and infant development is dependent on an adequate maternal supply of essential and polyunsaturated fatty acids (PUFA). While there are published data on the fatty acid status of pregnant women, there are few on the status of non-pregnant women of reproductive age. The aims of this study were to test the hypotheses that the fatty acid status of non-pregnant women is affected by socio-economic status and anthropometric, behavioural and obstetric factors.Design: Observational studyMethods: One-hundred and thirty-five women of child-bearing age (mean 29.8 y, s.d. 6.92) were invited to provide a blood sample and to answer a questionnaire, of whom 114 were included in the study. Plasma and red cell total fatty acids were measured as their methyl esters by gas chromatography mass spectrometry.Results: On multivariate analyses, use of hormonal contraception was independently associated with lower plasma polyunsaturated fatty acids (difference between means −2.76, 95% confidence interval (−4.64, −0.88), P=0.0034), whereas cigarette smoking was associated with higher red cell oleic acid (0.74 (0.18, 1.29), P=0.0094). Fish intake was associated with higher red cell total n-3 fatty acids (0.62 (0.27, 0.85), P=0.0014).Conclusions: We have reported data on the range of the fatty acids of plasma and red blood cells (RBC) total lipids of 114 healthy women of reproductive age. These data provide further information on how socio-economic, anthropometric, behavioural and obstetric factors may be relevant to female and nutrition and health.Sponsorship: University of Glasgow.European Journal of Clinical Nutrition (2001) 55, 518–524