Cornelia H.M. van Jaarsveld

Eating rate is a heritable phenotype related to weight in children

BACKGROUND There is growing interest in the heritability of behavioral phenotypes related to adiposity. One potential candidate is the speed of eating, although existing evidence for an association with weight is mixed. OBJECTIVE We aimed to assess the speed of eating in a sample of 10-12-y-old children to test the hypotheses that higher eating rate is related to greater adiposity and that eating rate is a heritable characteristic. DESIGN Video data of 254 twin children eating a standard meal at home were used to record eating rate (bites/min) and changes in eating rate across the 4 quarters of the meal. Adiposity was indexed with body mass index SD scores relative to British 1990 norms; for some analyses, children were categorized into groups of overweight or obese and into 2 subgroups of normal-weight (lower normal-weight or higher normal-weight) for comparison of the eating rate within the normal range as well as between clinical and nonclinical groups. All analyses controlled for clustering in twin pairs. Heritability of eating rate was modeled by using standard twin methods. RESULTS There was a significant linear association across the 3 weight groups for eating rate (P = 0.010), and regression analyses showed that eating rate increased by 0.18 bites/min for each 1-unit increase in body mass index SD score (P = 0.005). The heritability of eating rate was high (0.62; 95% CI: 0.45, 0.74). There was no association between weight group and a change (ie, deceleration) in eating rate over the mealtime. CONCLUSION Faster eating appears to be a heritable behavioral phenotype related to higher weight.

Development of Overweight in Children in Relation to Parental Weight and Socioeconomic Status

The purpose of the study was to test the hypothesis that socioeconomic status (SES) moderates the association between parental weight and changes in BMI from childhood to early adolescence. Participants included 428 twin children from 100 families with obese parents (“obese families”) and 114 sociodemographically matched families with normal‐weight parents (“lean families”) who were assessed in their homes (age = 4.4). Follow‐up study was conducted 7 years later (age = 11.2) on 346 children (81%). Complete data were available for 333 children. Family SES was indexed with maternal education. Childrens weights and heights were measured to calculate BMI s.d. scores based on 1990 British norms. Overweight was defined as >91st BMI centile. In children with obese parents, BMI s.d. scores increased from 0.51 at age 4 to 1.06 at age 11. In children with lean parents, BMI s.d. scores decreased from 0.11 to 0.05. Prevalence of overweight remained stable from age 4 to 11 in children with lean parents (8% to 9%), but it more than doubled in children with obese parents (17% to 45%). There was a significant interaction between parental weight and family SES (P < 0.01), so that in children with lean parents there was no SES difference in the BMI status from age 4 to 11; however, in children with obese parents, the increase in adiposity was significantly greater in lower SES families. These results suggest that parental leanness confers significant protection against development of overweight in children regardless of family SES, while parental obesity is an adverse prognostic sign, especially in lower SES families.

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.

Maternal Education Is Associated with Feeding Style

Maternal feeding styles may be influenced by maternal education, with implications for childrens dietary quality and adiposity. One-hundred and eighty mothers completed the Parental Feeding Style Questionnaire, which includes scales assessing four aspects of feeding style, ie, control over feeding, emotional feeding, instrumental feeding, and encouragement/prompting to eat. Mothers with higher education had significantly higher scores on control over feeding [F(1,177)=8.79; P=0.003] and significantly lower emotional feeding scores [F(1,177)=7.26; P=0.008] than those with lower education. There were no differences for instrumental feeding or encouragement/prompting to eat (P>0.05). These findings suggest modest but potentially important differences in maternal control and emotional feeding styles by maternal education. Should these feeding characteristics prove salient to childhood diet and weight, this could inform appropriately targeted parental feeding advice.

Socioeconomic status and weight gain in early infancy

Context:The association between low socioeconomic status (SES) and childhood obesity foreshadows lifelong inequalities in health. Insight into the causal mechanisms linking childhood adversity to long-term health could be provided by discovering when the negative SES gradient in weight emerges and what early life experiences are associated with it.Objective:SES differences in infant weight gain in the first 3 months of life were examined, and contributions of parental body mass index, maternal smoking and feeding method to this association were assessed.Design:Observational study using longitudinal weight data from 2402 families taking part in the Gemini Study; a twin birth cohort recruited from all twin births between March and December 2007 in England and Wales.Outcome measures:Infant weights at birth and 3 months converted to standard deviation scores (SDS), change in weight SDS and rapid growth. SES was indexed by occupation and maternal education.Results:There were no SES differences in birth weight, but lower SES was associated with higher 3-month weight, greater change in weight and a higher prevalence of rapid growth (all P<0.01), with graded associations across levels of SES. Including parental overweight or smoking in pregnancy in the regression model did not affect the association between SES and weight gain, but including feeding method attenuated the SES effect on weight gain by at least 62% and rendered it nonsignificant.Conclusion:The foundations for lifelong socioeconomic inequalities in obesity risk may be laid in early infancy, with infant-feeding practices having a part in the diverging weight trajectories.

Perceived stress and weight gain in adolescence: a longitudinal analysis.

Although perceived stress has been hypothesized to be a risk factor for obesity, epidemiological studies relating stress to weight gain have shown mixed results. We examined prospective associations between perceived stress and changes in waist circumference and BMI in a large study of adolescents. As part of the Health and Behaviour in Teenagers Study (HABITS), height, weight, and waist circumference were measured annually in 4,065 adolescents aged from 11 to 16. Waist and BMI standard deviation scores (SDS) were used as indices of adiposity. Adolescents completed a measure of perceived stress each year, from which mean stress scores over the 5‐year period were also calculated and divided by tertile into lower, moderate, and higher stress. Associations between perceived stress at each year and adiposity 1–4 years later and also adiposity trajectories over the whole period in relation to mean stress were investigated. Analyses were adjusted for age, sex, ethnicity, socioeconomic deprivation, pubertal timing, and smoking. Perceived stress in any year was not related prospectively to increases in waist or BMI SDS 1–4 years later, nor was there any evidence that higher stress over the whole period was associated with greater gains in waist or BMI SDS. However, waist and BMI SDS were significantly higher in the moderate‐ and higher‐stress groups than the lower‐stress group across the whole 5‐year period. Persistent stress was associated with higher waist circumference and BMI in adolescence, but did not lead to differential changes over 5 years.

Childhood obesity trends from primary care electronic health records in England between 1994 and 2013: population-based cohort study

Objective This study aimed to use primary care electronic health records to evaluate the prevalence of overweight and obesity in 2–15-year-old children in England and compare trends over the last two decades. Design Cohort study of primary care electronic health records. Setting 375 general practices in England that contribute to the UK Clinical Practice Research Datalink. Patients Individual participants were sampled if they were aged between 2 and 15 years during the period 1994–2013 and had one or more records of body mass index (BMI). Main outcome measure Prevalence of overweight (including obesity) was defined as a BMI equal to or greater than the 85th centile of the 1990 UK reference population. Results Data were analysed for 370 544 children with 507 483 BMI records. From 1994 to 2003, the odds of overweight and obesity increased by 8.1% per year (95% CI 7.2% to 8.9%) compared with 0.4% (−0.2% to 1.1%) from 2004 to 2013. Trends were similar for boys and girls, but differed by age groups, with prevalence stabilising in 2004 to 2013 in the younger (2–10 year) but not older (11–15 year) age group, where rates continued to increase. Conclusions Primary care electronic health records in England may provide a valuable resource for monitoring obesity trends. More than a third of UK children are overweight or obese, but the prevalence of overweight and obesity may have stabilised between 2004 and 2013.

Marriage and cancer prevention: does marital status and inviting both spouses together influence colorectal cancer screening participation?

Objectives This study examined the influence of marital status and inviting both partners together on participation in colorectal cancer screening. Setting Data were from a subset of participants from the UK Flexible Sigmoidoscopy Trial (1996–1999). Methods Marital status was self-reported, and co-invitation of partner was obtained from the trial database. Screening intentions were assessed in 16,527 adults aged 55–64 years. Attendance was recorded in the 4130 respondents who were subsequently invited. Results Multivariate analyses, controlling for age and educational level, indicate that married (or cohabiting) people have more positive intentions (odds ratio [OR] 1.26; 95% confidence interval [CI] 1.14–1.38) and higher attendance rates at screening (OR = 1.23; 95% CI 1.04–1.45) than non-married people. After adjusting for the marriage effect, inviting partners together (co-invitation) significantly increased screening intentions among women (OR = 1.17; 95% CI 1.04–1.31) but not men (OR = 0.97; 95% CI 0.85–1.10). Co-invitation significantly increased attendance at screening in both genders (OR = 1.34; 95% CI 1.14–1.58). Conclusions In this age group, married adults are more likely to participate in colorectal cancer screening than the non-married, and inviting both members of a couple together further increases screening uptake. The positive effect of marriage was as strong for women as men.

Prospective associations between appetitive traits and weight gain in infancy

BACKGROUND Differences in appetitive traits such as food-cue or satiety responsiveness have been hypothesized to contribute to variability in weight gain. However, existing data were largely cross-sectional and could not exclude the possibility that differences in appetitive traits were consequences of differences in weight. OBJECTIVE We tested whether prospective associations between appetitive traits and subsequent weight were stronger than associations between weight and subsequent appetitive traits. DESIGN Data were from Gemini, which is a population-based cohort of 2402 families with twins. Parents completed a Baby Eating Behavior Questionnaire to assess 4 appetitive traits for each twin at ages 3 and 15 mo. We obtained infant weights at 3, 9, and 15 mo from records of health professionals. Weight SD scores were calculated by using UK 1990 reference data. A path analysis was used to examine prospective associations in each direction over sequential 6-mo intervals and over the same 12-mo period, with the significance of differences between the 2 paths established with bootstrapping. RESULTS Path analyses included 2213 infants. For each appetitive trait, the path to subsequent weight (standardized coefficients: 0.17-0.33) was significantly larger than the path from weight to subsequent appetite (coefficients: 0.07-0.13). Results were confirmed when both associations were analyzed by using changes from 3 to 15 mo. CONCLUSION Longitudinal analyses showed that associations between appetitive traits and subsequent weight were stronger than between weight and subsequent appetite, which supports the idea that differences in appetitive traits, in conjunction with environmental opportunities to overeat, influence weight gain in early childhood.

Persistent impact of pubertal timing on trends in smoking, food choice, activity, and stress in adolescence.

Objectives: a) To replicate the established association between early puberty and smoking; b) to see whether differences between early and late maturers narrowed with increasing age and differed by gender; and c) to determine whether other health behaviors (food choice, physical activity, sedentary behavior) and stress showed the same association with pubertal timing. Methods: The Health and Behaviour in Teenagers Study (HABITS) followed a cohort of 5863 adolescents from ages 11 to 12 years (UK year 7; US grade 6) for 5 years. Puberty was assessed with the Pubertal Development Scale. Three pubertal timing groups were created by identifying adolescents who reached midpuberty relatively early, average, or late, compared with their peers. Longitudinal trends in health behaviors and stress were compared between the three groups. Results: Smoking rates were higher throughout adolescence among early-maturing students, with no evidence that late-maturers “caught up” when they reached puberty, although group differences narrowed over time. Early-maturing students had higher rates of sedentary behaviors but also reported higher rates of vigorous activity than their “on-time” developing counterparts. Patterns in dietary behaviors and stress showed lower rates of daily breakfast and higher stress among early-maturing girls, but not boys. Overall, the effects were largest in early adolescence (ages 11–13 years) and became smaller at older ages (ages 14–16 years). Conclusion: Early-maturing adolescents are at increased risk for unhealthy behaviors, especially smoking, and although differences attenuate during adolescence, they remain significant at age 16 years. This suggests that early maturation may be a cause of, or is at least a marker for, differences in lifestyle. HABITS = Health and Behaviour in Teenagers Study; OR = odds ratio; CI = confidence interval.