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There is increasing interest in modelling longitudinal dietary data and classifying individuals into subgroups (latent classes) who follow similar trajectories over time. These trajectories could identify population groups and time points amenable to dietary interventions. This paper aimed to provide a comparison and overview of two latent class methods: group-based trajectory modelling (GBTM) and growth mixture modelling (GMM). Data from 2963 mother-child dyads from the longitudinal Southampton Women's Survey were analysed. Continuous diet quality indices (DQI) were derived using principal component analysis from interviewer-administered FFQ collected in mothers pre-pregnancy, at 11- and 34-week gestation, and in offspring at 6 and 12 months and 3, 6-7 and 8-9 years. A forward modelling approach from 1 to 6 classes was used to identify the optimal number of DQI latent classes. Models were assessed using the Akaike and Bayesian information criteria, probability of class assignment, ratio of the odds of correct classification, group membership and entropy. Both methods suggested that five classes were optimal, with a strong correlation (Spearman's = 0·98) between class assignment for the two methods. The dietary trajectories were categorised as stable with horizontal lines and were defined as poor (GMM = 4 % and GBTM = 5 %), poor-medium (23 %, 23 %), medium (39 %, 39 %), medium-better (27 %, 28 %) and best (7 %, 6 %). Both GBTM and GMM are suitable for identifying dietary trajectories. GBTM is recommended as it is computationally less intensive, but results could be confirmed using GMM. The stability of the diet quality trajectories from pre-pregnancy underlines the importance of promotion of dietary improvements from preconception onwards.

Background: Physical activity (PA) has many health benefits, but motherhood is often associated with reduced PA. Considering that ages and number of children may be associated with maternal PA, and that PA patterns may change as children transition to formal schooling, we aimed to investigate the associations between ages and number of children and device-measured maternal PA., Methods: Cross-sectional analyses were conducted using data from 848 mothers from the Southampton Women's Survey at two different timepoints. Two-level random intercept linear models were used to investigate associations between ages (≤4y(ears) ("younger"), school-aged, both age groups) and number (1, 2, ≥3) of children, and their interaction, and accelerometer-assessed minutes of maternal moderate or vigorous PA (log-transformed MVPA) and light, moderate or vigorous PA (LMVPA)., Results: Women with any school-aged children engaged in more MVPA than those with only ≤4y (e.g. % difference in minutes of MVPA [95% confidence interval]: 46.9% [22.0;77.0] for mothers with only school-aged vs only ≤4y). Mothers with multiple children did less MVPA than those with 1 child (e.g. 12.5% [-1.1;24.3] less MVPA for those with 2 children). For mothers with multiple children, those with any school-aged children did less LMVPA than those with only ≤4y (e.g. amongst mothers with 2 children, those with only school-aged children did 34.0 [3.9;64.1] mins/day less LMVPA). For mothers with any ≤4y, those with more children did more LMVPA (e.g. amongst mothers with only ≤4y, those with 2 children did 42.6 [16.4;68.8] mins/day more LMVPA than those with 1 child)., Conclusions: Mothers with multiple children and only children aged ≤4y did less MVPA. Considering that many of these women also did more LMVPA than mothers with fewer or older children, interventions and policies are needed to increase their opportunities for higher intensity PA to maximise health benefits., Trial Registration: ClinicalTrials.gov Identifier: NCT04715945., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: CC received personal fees from Alliance for Better Bone Health, Amgen, Eli Lilly, GSK, Medtronic, Novartis, Pfizer, Roche, Servier, Takeda and UCB. KMG has received reimbursement for speaking at conferences sponsored by companies selling nutritional products, and is part of an academic consortium that has received research funding from Abbott Nutrition, Nestec, BenevolentAI Bio Ltd. and Danone. NCH has received consultancy, lecture fees and honoraria from Alliance for Better Bone Health, AMGEN, MSD, Eli Lilly, Servier, UCS, Shire, Consilient Healthcare, Kyowa Kirin and Internis Pharma. The remaining authors declare they have no competing interests. This does not alter our adherence to PLOS ONE policies on sharing data and materials., (Copyright: © 2022 Simpson et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Physical activity decreases through childhood, adolescence and into adulthood: parents of young children are particularly inactive, potentially negatively impacting their children's activity levels. This study aimed to determine the association between objectively measured maternal and 6-year-old children's physical activity; explore how this association differed by demographic and temporal factors; and identify change during the transition to school (from age 4-6)., Methods: Data were from the UK Southampton Women's Survey. Physical activity of 530 6-year-olds and their mothers was measured concurrently using accelerometry for ≤7 days. Cross-sectionally, two-level mixed-effects linear regression was used to model the association between maternal-child daily activity behaviour at age 6 [minutes sedentary (SED); in moderate-to-vigorous physical activity (MVPA)]. Interactions with demographic factors and time of the week were tested; how the association differed across the day was also explored. Change in the association between maternal-child physical activity (from age 4-6) was assessed in a subset (n = 170) [outcomes: SED, MVPA and light physical activity (LPA)]., Results: Mother-child daily activity levels were positively associated (SED: β = 0.23 [0.20, 0.26] minutes/day; MVPA: 0.53 [0.43, 0.64] minutes/day). The association was stronger at weekends (vs. weekdays) (interaction term: SED: β i  = 0.07 [0.02, 0.12]; MVPA: 0.44 [0.24, 0.64]). For SED, the association was stronger for those children with older siblings (vs. none); for MVPA, a stronger association was observed for those who had both younger and older siblings (vs. none) and a weaker relationship existed in spring compared to winter. Longitudinally, the association between mother-child activity levels did not change for SED and LPA. At age 6 (vs. age 4) the association between mother-child MVPA was weaker across the whole day (β i : - 0.16 [- 0.31, - 0.01]), but remained similar at both ages between 3 and 11 pm., Conclusions: More active mothers have more active 6-year-olds; this association was similar for boys and girls but differed by time of week, season and by age of siblings at home. Longitudinally, the association weakened for MVPA between 4 and 6 years, likely reflecting the differing activities children engage in during school hours and increased independence. Family-based physical activity remains an important element of children's activity behaviour regardless of age. This could be exploited in interventions to increase physical activity within families.

Objective: To test the hypothesis that maternal psychological profiles relate to children's quality of diet., Design: Cross-sectional study. Mothers provided information on their health-related psychological factors and aspects of their child's mealtime environment. Children's diet quality was assessed using an FFQ from which weekly intakes of foods and a diet Z-score were calculated. A high score described children with a better quality diet. Cluster analysis was performed to assess grouping of mothers based on psychological factors. Mealtime characteristics, describing how often children ate while sitting at a table or in front of the television, their frequency of takeaway food consumption, maternal covert control and food security, and children's quality of diet were examined, according to mothers' cluster membership., Subjects: Mother-child pairs (n 324) in the Southampton Initiative for Health. Children were aged 2-5 years., Setting: Hampshire, UK., Results: Two main clusters were identified. Mothers in cluster 1 had significantly higher scores for all psychological factors than mothers in cluster 2 (all P < 0.001). Clusters were termed 'more resilient' and 'less resilient', respectively. Children of mothers in the less resilient cluster ate meals sitting at a table less often (P = 0.03) and watched more television (P = 0.01). These children had significantly poorer-quality diets (β = -0.61, 95% CI -0.82, -0.40, P ≤ 0.001). This association was attenuated, but remained significant after controlling for confounding factors that included maternal education and home/mealtime characteristics (P = 0.006)., Conclusions: The study suggests that mothers should be offered psychological support as part of interventions to improve children's quality of diet.

Objectives: To investigate the association between objectively measured maternal and preschool-aged children's physical activity, determine how this association differs by demographic and temporal factors, and identify factors associated with maternal activity levels., Methods: In the UK Southampton Women's Survey, physical activity levels of 554 4-year-olds and their mothers were measured concurrently by using accelerometry for ≤7 days. Two-level mixed-effects linear regression was used to model the association between maternal and children's minutes spent sedentary, in light (LPA) and moderate-to-vigorous physical activity (MVPA). Linear regression was used to investigate correlates of maternal activity., Results: Mother-child daily activity levels were positively associated at all activity intensities (sedentary, LPA, and MVPA; all P < .001). The association for sedentary time was stronger for normal-weight children (versus those who were overweight/obese), and those attending preschool part-time (versus full-time). The mother-child association for LPA differed by maternal education and was stronger at the weekend (versus weekdays). The opposite was true for MVPA. Sedentary time and MVPA were most strongly associated in mornings, with LPA most strongly associated in the evenings. Maternal BMI, age leaving school, number and age of children at home, and working hours were independently associated with maternal daily sedentary time and LPA., Conclusions: Physical activity levels in mothers and their 4-year-old children are directly associated, with associations at different activity intensities influenced by temporal and demographic factors. Influences on maternal physical activity levels also differ by activity intensity. Providing targeted interventions for mothers of young children may increase both groups' activity.

Background: Factors associated with parental awareness of children's physical activity (PA) levels have not been explored in preschool-aged children. This paper investigates maternal awareness of preschool-aged children's PA levels and determined correlates associated with maternal overestimation of PA., Methods: Data from the Southampton Women's Survey, a UK population-based study, were collected March 2006 through June 2009. Daily minutes of moderate-to-vigorous PA (MVPA) were derived using accelerometry in 478 4-year-old children. Mothers who were realistic or overestimated their child's PA were identified. Log-binomial regression was used to analyse correlates of maternal overestimation of PA levels in children whose mothers perceived them to be active (n = 438)., Results: 40.8% of children were classified as inactive: 89.7% of these were perceived to be active by their mothers (over-estimators). These mothers were more likely to think their child sometimes lacked skills required to be physically active (RR (95% CI) = 1.29(1.03-1.63)) and their child was more likely to attend nursery full-time (RR = 1.53(1.14-2.04)). They were less likely to have older children at home (RR = 0.71(0.56-0.90))., Conclusions: Almost 90% of mothers of inactive preschool-aged children perceive their child to be active. Nursery-school attendance and having older siblings at home may be important to consider when designing behavioural interventions to increase PA in preschool children.

Background: Obesity and asthma have increased in westernised countries. Maternal obesity may increase childhood asthma risk. If this relation is causal, it may be mediated through factors associated with maternal adiposity, such as fetal development, pregnancy complications or infant adiposity. We investigated the relationships of maternal body mass index (BMI) and fat mass with childhood wheeze, and examined the influences of infant weight gain and childhood obesity., Methods: Maternal prepregnancy BMI and estimated fat mass (from skinfold thicknesses) were related to asthma, wheeze and atopy in 940 children. Transient or persistent/late wheeze was classified using questionnaire data collected at ages 6, 12, 24 and 36 months and 6 years. At 6 years, skin-prick testing was conducted and exhaled nitric oxide and spirometry measured. Infant adiposity gain was calculated from skinfold thickness at birth and 6 months., Results: Greater maternal BMI and fat mass were associated with increased childhood wheeze (relative risk (RR) 1.08 per 5 kg/m(2), p=0.006; RR 1.09 per 10 kg, p=0.003); these reflected associations with transient wheeze (RR 1.11, p=0.003; RR 1.13, p=0.002, respectively), but not with persistent wheeze or asthma. Infant adiposity gain was associated with persistent wheeze, but not significantly. Adjusting for infant adiposity gain or BMI at 3 or 6 years did not reduce the association between maternal adiposity and transient wheeze. Maternal adiposity was not associated with offspring atopy, exhaled nitric oxide, or spirometry., Discussion: Greater maternal adiposity is associated with transient wheeze but not asthma or atopy, suggesting effects upon airway structure/function but not allergic predisposition.

Background The pattern of change in maternal bone turnover throughout pregnancy is poorly characterized. Objectives We investigated changes across pregnancy in a marker of maternal bone resorption, urinary C-terminal telopeptide of type I collagen (CTX), the influence of gestational vitamin D supplementation, and associations between CTX and maternal postnatal bone indices. Methods MAVIDOS (the Maternal Vitamin D Osteoporosis Study) is a randomized, double-blind, placebo-controlled trial of 1000 IU cholecalciferol/d compared with placebo from 14 weeks of gestation to birth. Maternal second-void urinary α- and β-CTX were measured (ELISA) at 14 and 34 weeks of gestation; DXA was performed within 2 wk postpartum. The Mann–Whitney Rank Sum test, Spearman's rank correlation, and linear regression were used to compare median CTX values within and between groups from early to late pregnancy, and associations with maternal bone outcomes. Results In total, 372 women had CTX and 25-hydroxyvitamin D [25(OH)D] measured in early and late pregnancy. CTX at 14 and 34 weeks of gestation were correlated in both placebo (r  = 0.31) and cholecalciferol (r  = 0.45) groups (P  < 0.0001). Median CTX increased from 14 to 34 weeks of gestation in both groups (n  = 372 total) [placebo (n  = 188): from 223.6 to 449.7 μg/mmol creatinine; cholecalciferol (n  = 184): from 222.3 to 419.3 μg/mmol creatinine; P  = 0.03 for placebo compared with cholecalciferol difference in CTX at 34 weeks of gestation]. The conditional mean ± SD increase in CTX [z-score (SD)] from early to late pregnancy was greater in the placebo group (n  = 188) than in the cholecalciferol group (n  = 184) (placebo: 0.16 ± 0.92; cholecalciferol: −0.16 ± 1.06; P -difference < 0.01). Higher CTX at 34 weeks of gestation was associated, similarly in both groups, with lower maternal total hip and lumbar spine bone mineral content and bone mineral density (BMD) (e.g. lumbar spine BMD: β = −0.02 g · cm−2 · SD−1 increase in CTX; 95% CI: −0.027, −0.002 g · cm−2 · SD−1; P  = 0.02, n  = 283). Conclusions Maternal urinary CTX, a bone resorption marker, rises through pregnancy, although to a lesser degree with gestational cholecalciferol supplementation, and is inversely associated with maternal bone mass postpartum. This trial was registered at www.isrctn.com as ISRCTN 82927713 and eudract.ema.europa.eu as EudraCT 2007-001716-23. [ABSTRACT FROM AUTHOR]

Background: Choline status has been positively associated with weight and fat mass in animal and human studies. As evidence examining maternal circulating choline concentrations and offspring body composition in human infants/children is lacking, we investigated this in two cohorts.Methods: Maternal choline concentrations were measured in the UK Southampton Women's Survey (SWS; serum, n = 985, 11 weeks' gestation) and Singapore Growing Up Towards healthy Outcomes (GUSTO); n = 955, 26-28 weeks' gestation) mother-offspring cohorts. Offspring anthropometry was measured at birth and up to age 5 years. Body fat mass was determined using dual-energy x-ray absorptiometry at birth and age 4 years for SWS; and using air-displacement plethysmography at birth and age 5 years for GUSTO. Linear-regression analyses were performed, adjusting for confounders.Results: In SWS, higher maternal choline concentrations were associated with higher neonatal total body fat mass {β = 0.60 standard deviation [SD]/5 µmol/L maternal choline [95% confidence interval (CI) 0.04-1.16]} and higher subscapular skinfold thickness [β = 0.55 mm/5 µmol/L (95% CI, 0.12-1.00)] at birth. In GUSTO, higher maternal choline concentrations were associated with higher neonatal body mass index-for-age z-score [β = 0.31 SD/5 µmol/L (0.10-0.51)] and higher triceps [β = 0.38 mm/5 µmol/L (95% CI, 0.11-0.65)] and subscapular skinfold thicknesses [β = 0.26 mm/5 µmol/L (95% CI, 0.01-0.50)] at birth. No consistent trends were observed between maternal choline and offspring gain in body mass index, skinfold thicknesses, abdominal circumference, weight, length/height and adiposity measures in later infancy and early childhood.Conclusion: Our study provides evidence that maternal circulating choline concentrations during pregnancy are positively associated with offspring BMI, skinfold thicknesses and adiposity at birth, but not with growth and adiposity through infancy and early childhood to the age of 5 years. [ABSTRACT FROM AUTHOR]

Background: The role of maternal 25-hydroxyvitamin D [25(OH)D] in fetal development is uncertain, and findings of observational studies have been inconsistent. Most studies have assessed 25(OH)D only one time during pregnancy, but to our knowledge, the tracking of an individual's 25(OH)D during pregnancy has not been assessed previously. Objective: We determined the tracking of serum 25(OH)D from early to late pregnancy and factors that influence this. Design: The Southampton Women's Survey is a prospective mother-offspring birth-cohort study. Lifestyle, diet, and 25(OH)D status were assessed at 11 and 34 wk of gestation. A Fourier transformation was used to model the seasonal variation in 25(OH)D for early and late pregnancy separately, and the difference between the measured and seasonally modeled 25(OH)D was calculated to generate a season-corrected 25(OH)D. Tracking was assessed with the use of the Pearson correlation coefficient, and multivariate linear regression was used to determine factors associated with the change in season-corrected 25(OH)D. Results: A total of 1753 women had 25(OH)D measured in both early and late pregnancy. There was a moderate correlation between season-corrected 25(OH)D measurements at 11 and 34 wk of gestation (r = 0.53, P, 0.0001; n = 1753). Vitamin D supplementation was the strongest predictor of tracking; in comparison with women who never used supplements, the discontinuation of supplementation after 11 wk was associated with a reduction in season-corrected 25(OH)D (β = 27.3 nmol/L; P, 0.001), whereas the commencement (β = 12.6 nmol/L; P, 0.001) or continuation (β = 6.6 nmol/L; P, 0.001) of supplementation was associated with increases in season-corrected 25(OH)D. Higher pregnancy weight gain was associated with a reduction in season-corrected 25(OH)D (β = 20.4 nmol µ L-1 µ kg-1; P = 0.015), whereas greater physical activity (β = 0.4 nmol/L per h/wk; P = 0.011) was associated with increases. Conclusions: There is a moderate tracking of 25(OH)D status through pregnancy; factors such as vitamin D supplementation, weight gain, and physical activity are associated with changes in season-corrected 25(OH)D from early to late gestation. These findings have implications for study designs and analyses and approaches to intervention studies and clinical care. [ABSTRACT FROM AUTHOR]

Background: Early life may be a "critical period" when appetite and regulation of energy balance are programmed, with lifelong consequences for obesity risk. Insight into the potential impact of modifying early-life risk factors on later obesity can be gained by evaluating their combined effects. Objective: The objective was to examine the relation between the number of early-life risk factors and obesity outcomes among children in a prospective birth cohort (Southampton Women's Survey). Design: Five risk factors were defined: maternal obesity [prepregnant body mass index (BMI; in kg/m²) .30], excess gestational weight gain (Institute of Medicine, 2009), smoking during pregnancy, low maternal vitamin D status (<64 nmol/L), and short duration of breastfeeding (none or <1 mo). Obesity outcomes examined when the children were aged 4 and 6 y were BMI, dual-energy X-ray absorptiometry-assessed fat mass, overweight, or obesity (International Obesity Task Force). Data were available for 991 mother-child pairs, with children born between 1998 and 2003. Results: Of the children, 148 (15%) had no early-life risk factors, 330 (33%) had 1, 296 (30%) had 2, 160 (16%) had 3, and 57 (6%) had 4 or 5. At both 4 and 6 y, there were positive graded associations between number of early-life risk factors and each obesity outcome (all P < 0.001). After taking account of confounders, the relative risk P of being overweight or obese for children who had 4 or 5 risk factors was 3.99 (95% CI: 1.83, 8.67) at 4 y and 4.65 (95% CI: 2.29, 9.43) at 6 y compared with children who had none (both P < 0.001). P Conclusions: Having a greater number of early-life risk factors was associated with large differences in adiposity and risk of overweight and obesity in later childhood. These findings suggest that early intervention to change these modifiable risk factors could make a significant contribution to the prevention of childhood obesity. [ABSTRACT FROM AUTHOR]

Background: Correlates of physical activity (PA) are hypothesized to be context and behaviour specific, but there is limited evidence of this in young children. The aim of the current study is to investigate associations between personal, social and environmental factors and objectively measured light and moderate-to-vigorous PA (LPA and MVPA, respectively) in four-year-old children. Methods: Cross-sectional data were used from the Southampton Women’s Survey, a UK population-based longitudinal study. Four-year old children (n = 487, 47.0% male) had valid PA data assessed using accelerometry (Actiheart) and exposure data collected with a validated maternal questionnaire (including data on child personality, family demographics, maternal behaviour, rules and restrictions, and perceived local environment). Linear regression modelling was used to analyse associations with LPA and MVPA separately, interactions with sex were explored. Results: LPA minutes were greater in children whose mothers reported more PA (vs. inactive: regression coefficient±standard error: 6.70±2.94 minutes), and without other children in the neighbourhood to play with (−6.33±2.44). MVPA minutes were greater in children with older siblings (vs. none: 5.81±2.80) and those whose mothers used active transport for short trips (vs. inactive: 6.24±2.95). Children accumulated more MVPA in spring (vs. winter: 9.50±4.03) and, in boys only, less MVPA with availability of other children in the neighbourhood (−3.98±1.70). Discussion: Young children’s LPA and MVPA have differing associations with a number of social and environmental variables. Interventions targeting PA promotion in young children outside of formal care settings should consider including intensity specific factors. [ABSTRACT FROM AUTHOR]

Background: Low vitamin D status has been linked to adiposity, but little is known of the effects of low status in pregnancy on offspring body composition. Objective: The objective was to determine how maternal vitamin D status relates to lean and fat mass of the offspring. Design: The offspring of 977 pregnant women, who had serum 25-hydroxyvitamin D [25(OH)D] measured at 34 wk gestation, were followed up within 3 wk of birth and at 4 and 6 y of age for dual- energy X-ray absorptiometry assessment of lean and fat mass. Results: The median maternal serum 25(OH)D concentration was 62 nmol/L (IQR: 43-89 nmol/L); 35% of the women studied had values <50 nmol/L. Lower vitamin D status was associated with lower fat mass in the offspring at birth but with greater fat mass at ages 4 and 6 y. It was not associated with lean mass at any of the ages studied. The opposing associations seen between maternal 25(OH)D (SDs) and fat mass (SDs) in the offspring at birth and at age 6 y were robust to adjustment for a range of confounding factors, including maternal BMI and weight gain in pregnancy [ß (95% CI): 0.08 (0.02, 0.15) and -0.10 (-0.17, -0.02), respectively]. The key independent predictors of higher maternal vitamin D status were season of assessment and use of vitamin D supplements. Conclusions: Lower maternal vitamin D status may be linked to programmed differences in offspring fat mass. The findings require replication but add to a growing evidence base for a role of vitamin D in the origins of adiposity. Am J Clin Nutr 2012;96:57-63. [ABSTRACT FROM AUTHOR]