Imogen Rogers

Early life risk factors for obesity in childhood: cohort study

Abstract Objective To identify risk factors in early life (up to 3 years of age) for obesity in children in the United Kingdom. Design Prospective cohort study. Setting Avon longitudinal study of parents and children, United Kingdom. Participants 8234 children in cohort aged 7 years and a subsample of 909 children (children in focus) with data on additional early growth related risk factors for obesity. Main outcome measures Obesity at age 7 years, defined as a body mass index 3 95th centile relative to reference data for the UK population in 1990. Results Eight of 25 putative risk factors were associated with a risk of obesity in the final models: parental obesity (both parents: adjusted odds ratio, 10.44, 95% confidence interval 5.11 to 21.32), very early (by 43 months) body mass index or adiposity rebound (15.00, 5.32 to 42.30), more than eight hours spent watching television per week at age 3 years (1.55, 1.13 to 2.12), catch-up growth (2.60, 1.09 to 6.16), standard deviation score for weight at age 8 months (3.13, 1.43 to 6.85) and 18 months (2.65, 1.25 to 5.59); weight gain in first year (1.06, 1.02 to 1.10 per 100 g increase); birth weight, per 100 g (1.05, 1.03 to 1.07); and short (< 10.5 hours) sleep duration at age 3 years (1.45, 1.10 to 1.89). Conclusion Eight factors in early life are associated with an increased risk of obesity in childhood.

The influence of birthweight and intrauterine environment on adiposity and fat distribution in later life

OBJECTIVE: To review the literature on the association between birthweight and body mass index (BMI) and obesity in later life.METHODS: Included in the review were papers appearing in Medline since 1966 and identified using the search terms obesity, body fat, waist, body constitution, birthweight and birth weight. Further papers were identified by examining bibliographies.RESULTS: There is good evidence that there is an association between birthweight and subsequent BMI and overweight in young adults and children, which is linear and positive in some studies and J- or U-shaped in others. The evidence is less strong for middle-aged subjects. Studies that have assessed lean body mass (LBM) and fat body mass have tended to find that birthweight is positively associated with LBM and negatively associated with relative adiposity. This suggests that the association between birthweight and BMI/overweight does not necessarily reflect increased adiposity at higher birthweights. On controlling for current body mass there is fairly consistent evidence of a negative association between birthweight and a central pattern of fat distribution as measured by central:peripheral skinfold ratios. It has been suggested that the prenatal period is a ‘critical’ period for the development of adiposity, but it is unclear how far associations between birthweight and subsequent body habitus are genetic in origin and how far they result from intrauterine ‘programming’. Two lines of evidence would suggest that the association is predominantly genetic. Studies of monozygotic twins have found environmentally determined differences in birthweight to be unrelated to subsequent BMI, and the association between birthweight and BMI is substantially reduced on controlling for parental BMI. However, some evidence of an influence of intrauterine environment on later obesity comes from studies of subjects who were exposed in utero to the effects of diabetes, famine conditions or smoking.CONCLUSIONS: The reasons for the positive association between birthweight and BMI remain unclear. More studies including accurate measurement of body composition are needed to assess how far this relation is accounted for by changes in fat mass or by changes in lean mass. Studies with accurate measures of parental BMI would also be useful in assessing the importance of this confounder.

Infancy weight gain predicts childhood body fat and age at menarche in girls.

CONTEXT Rapid postnatal weight gain has been associated with subsequent increased childhood adiposity. However, the contribution of rapid weight gain during specific infancy periods is not clear. OBJECTIVE We aimed to determine which periods of infancy weight gain are related to childhood adiposity and also to age at menarche in UK girls. DESIGN, SETTING, AND PARTICIPANTS A total of 2715 girls from a prospective UK birth cohort study participated in the study. MAIN OUTCOME MEASURES Routinely measured weights and lengths at ages 2, 9, and 19 months were extracted from the local child health computer database. Body composition was assessed by dual-energy x-ray absorptiometry at age 10 yr, and age at menarche was assessed by questionnaire (categorized into three groups: <12.0, 12.0-13.0, and >13.0 yr). RESULTS Faster early infancy weight gain between 0 and 2 months and also 2 to 9 months were associated with increased body fat mass relative to lean mass at age 10 yr and also with earlier age at menarche. Each +1 unit gain in weight sd score between 0 and 9 months was associated with an odds ratio (95% confidence interval) = 1.48 (1.27-1.60) for overweight (body mass index > 85th centile) at 10 yr, and 1.34 (1.21-1.49) for menarche at less than 12 yr. In contrast, subsequent weight gain between 9 and 19 months was not associated with later adiposity or age at menarche. CONCLUSIONS In developed settings, rapid weight gain during the first 9 months of life is a risk factor for both increased childhood adiposity and early menarche in girls.

Dietary patterns in pregnancy and associations with socio-demographic and lifestyle factors.

Objective:To obtain distinct dietary patterns in the third trimester of pregnancy using principal components analysis (PCA); to determine associations with socio-demographic and lifestyle factors.Design and methods:A total of 12 053 pregnant women partaking in a population-based cohort study recorded current frequency of food consumption via questionnaire in 1991–1992. Dietary patterns identified using PCA were related to social and demographic characteristics and lifestyle factors.Results:Five dietary patterns were established and labelled to best describe the types of diet being consumed in pregnancy. The ‘health conscious’ component described a diet based on salad, fruit, rice, pasta, breakfast cereals, fish, eggs, pulses, fruit juices, white meat and non-white bread. The ‘traditional’ component loaded highly on all types of vegetables, red meat and poultry. The ‘processed’ component was associated with high-fat processed foods. The ‘confectionery’ component was characterized by snack foods with high sugar content and the final ‘vegetarian’ component loaded highly on meat substitutes, pulses, nuts and herbal tea and high negative loadings were seen with red meat and poultry. There were strong associations between various socio-demographic variables and all dietary components; in particular, a ‘health conscious’ diet was positively associated with increasing education and age and non-white women. There was a negative association with increased parity, single, non-working women, those who smoked and who were overweight pre-pregnancy. Opposite associations were seen with the ‘processed’ component.Conclusions:Distinct dietary patterns in pregnancy have been identified. There is clear evidence of social patterning associated with the dietary patterns, these social factors need to be accounted for in future studies using dietary patterns. This study will form the basis for further work investigating pregnancy outcome.

Maternal macronutrient and energy intakes in pregnancy and offspring intake at 10 y: exploring parental comparisons and prenatal effects

Background: High maternal dietary intakes in pregnancy may lead to increased fetal growth and program neuroendocrine pathways that result in greater appetite, energy intake, and adiposity in offspring later in life. Few prospective dietary studies have explored this relation. Objective: The objective was to assess associations of maternal dietary intake in pregnancy and maternal and paternal dietary intake postnatally with child dietary intake and adiposity. Design: Dietary intakes of energy, protein, total fat, and carbohydrate were assessed prospectively in mothers during pregnancy, in mothers and their partners at 47 mo postnatally, and in children at 10 y (n = 5717 mother-child pairs prenatally, 5593 mother-child pairs postnatally, and 3009 father-child pairs). Child body composition was assessed at 9 and 11 y (n = 5725). Results: Maternal dietary intakes of protein, fat (when adjusted for energy intake), and carbohydrate in pregnancy were positively associated with child dietary intakes of the same nutrients, and these associations were greater than those observed for paternal dietary intake, which was not strongly associated with offspring diet. Associations of maternal prenatal-offspring intakes were stronger than those of maternal postnatal-offspring intakes for protein and fat. Greater child energy and macronutrient intakes were only associated with greater adiposity in children when adjusted for potential energy underreporting. Maternal diet during pregnancy was not associated with offspring adiposity or lean mass. Conclusion: The stronger prenatal maternal associations with child dietary intake, particularly protein and fat, compared with both paternal intake associations and maternal postnatal intake associations provide some evidence for in utero programming of offspring appetite by maternal intake during pregnancy.

Smoking during pregnancy and offspring fat and lean mass in childhood.

Objective: Maternal smoking during pregnancy has been shown to be associated with obesity in the offspring, but findings have been based mainly on BMI, which is derived from height and weight. This study examined the association between maternal and partner smoking during pregnancy and offspring total fat, truncal fat, and lean mass in childhood.

Trends in waist circumferences in young British children: a comparative study.

OBJECTIVE:To compare waist circumference (a measure of central fatness) and body mass index (BMI, a measure of general fatness) between a contemporary cohort and similar aged British children measured in 1987.DESIGN:Comparative study of two cohorts. The first was a cross-sectional survey and the second an ongoing longitudinal survey.SETTING:The cross-sectional study was conducted throughout Great Britain during 1987. The ongoing longitudinal study was conducted in the Avon region between 1995 and 1998.PARTICIPANTS:A total of 1821 children were measured in the cross-sectional study, and around 1000 children were measured in the longitudinal study. Ages ranged between 2 and 5 y.MAIN OUTCOME MEASURES:Waist circumference, height, weight and BMI. Values were expressed as mean±s.d. Age-related measures were compared.RESULTS:At equivalent ages, mean waist circumference values were greater in the contemporary children, compared with children measured in the earlier cross-sectional study in 1987 (P<0.05). Although boys from the contemporary cohort had the larger absolute waist circumference measurements, the absolute and percentage differences in waist circumference between the cohorts were greater for the girls. Mean BMI values were slightly but significantly higher in the contemporary children compared with children measured in the earlier cross-sectional study (P<0.05). The proportional increase in waist circumference for each age–sex group generally exceeded the proportional increase in BMI.CONCLUSION:These results suggest that central fatness in young British children has increased over the period of 1987–97 to a greater extent than general fatness. This should be of concern since evidence associates greater central adiposity with adverse levels of cardiovascular risk factors in children. Furthermore, the study highlights important shortcomings of the BMI measurement, in that it provides no information on body fat distribution and can mask true obesity-related risk in children.

Maternal fish intake in late pregnancy and the frequency of low birth weight and intrauterine growth retardation in a cohort of British infants

Objective: To investigate the relation between maternal fish intake in late pregnancy and the frequency of low birth weight and intrauterine growth retardation (IUGR). Participants: 11 585 pregnant women in south west England. Methods: Information on fish intake was obtained from a food frequency questionnaire sent to the women at 32 weeks’ gestation, and used to calculate n-3 fatty acid (n-3FA) intake from fish. IUGR was defined as a birth weight for gestational age and sex below the 10th centile. Confounding variables considered included maternal age, height, weight, education, parity, smoking and drinking in pregnancy, and whether the mother was living with a partner. Only singleton, liveborn infants were included. Main results: Mean daily intakes of fish and n-3FAs were 32.8 g and 0.147 g respectively. In unadjusted analyses there were positive associations between mean birth weight and fish intake or n-3FA intake, but these disappeared on adjustment for potential confounders. The frequency of IUGR decreased with increasing fish intake—the OR (95%CI) of IUGR in those eating no fish was 1.85 (1.44 to 2.38) compared with those in the highest fish intake group. On adjustment this relation was attenuated (adjusted OR 1.37 (1.02 to 1.84)), but the decline in the frequency of IUGR with increasing fish intake remained statistically significant. No relation was observed between mean gestation and fish or n-3FA intake. Conclusions: These results lend some support to the hypothesis that raising fish or n3-FA intake during pregnancy may increase fetal growth rate. However, they provide no evidence that increasing fish consumption is associated with an increase in mean gestation.

Influences on child fruit and vegetable intake: sociodemographic, parental and child factors in a longitudinal cohort study.

OBJECTIVE To examine the sociodemographic, parental and child factors that predict fruit and vegetable consumption in 7-year-old children. DESIGN Diet was assessed using three 1d unweighed food diaries. The childs daily fruit and vegetable consumption was calculated by summing the weight of each type of fruit, fruit juice and vegetable consumed. The various others factors measured were assessed by a questionnaire at different time points. SETTING The Avon Longitudinal Study of Parents and Children (ALSPAC). SUBJECTS A total of 7285 children aged 7 years residing in the south-west of England during 1999-2000. RESULTS Median daily fruit and vegetable consumption (201 g) was below the recommendations for this age group (320 g). Girls ate more fruit and vegetables per unit energy (30.3 g/MJ) than boys (26.7 g/MJ; P =< 0.001). The predictors of fruit and vegetable consumption were mostly similar. Fruit and vegetable consumption was associated with maternal consumption, maternal education status and parental rules about serving fruit/vegetables every day, food expenditure per person and whether the child was choosy about food. Vegetable consumption was also associated with the other characteristics of the child, such as whether the child enjoyed food and whether the child tried a variety of foods. CONCLUSIONS Children are not eating recommended amounts of fruit and vegetables, particularly boys. Consumption of fruit and vegetables appears to be influenced by parental rules about daily consumption and parental consumption and by the childs choosiness. Parents actions could influence this. These findings may prove useful for those planning healthy eating campaigns for children.

Dietary Energy Density Affects Fat Mass in Early Adolescence and Is Not Modified by FTO Variants

Background Dietary energy density (DED) does not have a simple linear relationship to fat mass in children, which suggests that some children are more susceptible than others to the effects of DED. Children with the FTO (rs9939609) variant that increases the risk of obesity may have a higher susceptibility to the effects of DED because their internal appetite control system is compromised. We tested the relationship between DED and fat mass in early adolescence and its interaction with FTO variants. Methods and Findings We carried out a prospective analysis on 2,275 children enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC). Diet was assessed at age 10 y using 3-day diet diaries. DED (kJ/g) was calculated excluding drinks. Children were genotyped for the FTO (rs9939609) variant. Fat mass was estimated at age 13 y using the Lunar Prodigy Dual-energy X-ray Absorptiometry scanner. There was no evidence of interaction between DED at age 10 y and the high risk A allele of the FTO gene in relation to fat mass at age 13 y (β = 0.005, p = 0.51), suggesting that the FTO gene has no effect on the relation between DED at 10 y and fat mass at 13 y. When DED at 10 y and the A allele of FTO were in the same model they were independently related to fat mass at 13 y. Each A allele of FTO was associated with 0.35±0.13 kg more fat mass at 13 y and each 1 kJ/g DED at 10 y was associated with 0.16±0.06 kg more fat mass at age 13 y, after controlling for misreporting of energy intake, gender, puberty, overweight status at 10 y, maternal education, TV watching, and physical activity. Conclusions This study reveals the multi-factorial origin of obesity and indicates that although FTO may put some children at greater risk of obesity, encouraging a low dietary energy density may be an effective strategy to help all children avoid excessive fat gain.