Helen Croker

Stress and dietary practices in adolescents

Baseline data from the Health and Behavior in Teenagers Study (HABITS) were used to investigate associations between stress and dietary practices in a socioeconomically and ethnically diverse sample of 4,320 schoolchildren (mean age = 11.83 years). Male (n = 2,578) and female (n = 1,742) pupils completed questionnaire measures of stress and 4 aspects of dietary practice (fatty food intake, fruit and vegetable intake, snacking, and breakfast consumption) and also provided demographic and anthropometric data. Multivariate analyses revealed that greater stress was associated with more fatty food intake, less fruit and vegetable intake, more snacking, and a reduced likelihood of daily breakfast consumption. These effects were independent of individual (gender, weight) and social (socioeconomic status, ethnicity) factors. Stress may contribute to long-term disease risk by steering the diet in a more unhealthy direction.

Lifestyle interventions for overweight and obese pregnant women to improve pregnancy outcome: systematic review and meta-analysis.

BackgroundOverweight and obesity pose a big challenge to pregnancy as they are associated with adverse maternal and perinatal outcome. Evidence of lifestyle intervention resulting in improved pregnancy outcome is conflicting. Hence the objective of this study is to determine the efficacy of antenatal dietary, activity, behaviour or lifestyle interventions in overweight and obese pregnant women to improve maternal and perinatal outcomes.MethodsA systematic review and meta-analyses of randomised and non-randomised clinical trials following prior registration (CRD420111122 http://www.crd.york.ac.uk/PROSPERO) and PRISMA guidelines was employed. A search of the Cochrane Library, EMBASE, MEDLINE, CINAHL, Maternity and Infant care and eight other databases for studies published prior to January 2012 was undertaken. Electronic literature searches, study selection, methodology and quality appraisal were performed independently by two authors. Methodological quality of the studies was assessed according to Cochrane risk of bias tool. All appropriate randomised and non-randomised clinical trials were included while exclusions consisted of interventions in pregnant women who were not overweight or obese, had pre-existing diabetes or polycystic ovarian syndrome, and systematic reviews. Maternal outcome measures, including maternal gestational weight gain, gestational diabetes and Caesarean section, were documented. Fetal outcomes, including large for gestational age and macrosomia (birth weight > 4 kg), were also documented.ResultsThirteen randomised and six non-randomised clinical trials were identified and included in the meta-analysis. The evidence suggests antenatal dietary and lifestyle intervention in obese pregnant women reduces maternal pregnancy weight gain (10 randomised clinical trials; n = 1228; -2.21 kg (95% confidence interval -2.86 kg to -1.59 kg)) and a trend towards a reduction in the prevalence of gestational diabetes (six randomised clinical trials; n = 1,011; odds ratio 0.80 (95% confidence interval 0.58 to 1.10)). There were no clear differences reported for other outcomes such as Caesarean delivery, large for gestational age, birth weight or macrosomia. All available studies were assessed to be of low to medium quality.ConclusionAntenatal lifestyle intervention is associated with restricted gestational weight gain and a trend towards a reduced prevalence of gestational diabetes in the overweight and obese population. These findings need to be interpreted with caution as the available studies were of poor to medium quality.

Changing perceptions of weight in Great Britain: comparison of two population surveys

Objectives To examine changes in public perceptions of overweight in Great Britain over an eight year period. Design Comparison of data on self perceived weight from population surveys in 1999 and 2007. Setting Household surveys of two representative samples in Great Britain. Participants 853 men and 944 women in 1999, and 847 men and 989 women in 2007. Main outcome measures Participants were asked to report their weight and height and classify their body size on a scale from “very underweight” to “obese.” Results Self reported weights increased dramatically over time, but the weight at which people perceived themselves to be overweight also rose significantly. In 1999, 81% of overweight participants correctly identified themselves as overweight compared with 75% in 2007, demonstrating a decrease in sensitivity in the self diagnosis of overweight. Conclusions Despite media and health campaigns aiming to raise awareness of healthy weight, increasing numbers of overweight people fail to recognise that their weight is a cause for concern. This makes it less likely that they will see calls for weight control as personally relevant.

Changing diet and physical activity to reduce gestational weight gain: a meta-analysis.

Excessive pregnancy weight gain is associated with adverse maternal and child health outcomes. Intervention developers have assumed that adopting a healthier diet and increasing physical activity in pregnancy can limit weight gain, but evaluations of such interventions have yielded mixed results. Recent reviews of this literature have not identified defining characteristics of effective interventions. We systematically reviewed 10 published controlled trials of interventions that aimed to reduce gestational weight gain through changes in diet or physical activity. Characteristics of the sample, intervention content and delivery, and methodology were categorized. Meta‐analysis showed that, overall, diet and physical activity change was effective in reducing gestational weight gain, but there was considerable heterogeneity in outcomes. Our analysis points to sample characteristics and aspects of intervention design, content, delivery and evaluation which differ between studies and may explain variation in effectiveness. Failure to evaluate changes in behaviour or its psychological determinants, and under‐reporting of intervention content, may obscure identification of the processes by which weight change is effected. This limits our ability to discern active intervention ingredients. We suggest that behaviour‐based gestational weight gain reduction interventions be more systematically designed, evaluated and reported to build on insights from behavioural science.

Eating for Pleasure or Profit The Effect of Incentives on Children’s Enjoyment of Vegetables

Parents commonly use rewards to encourage children to eat healthfully, but this practice remains controversial because rewards are suspected of undermining children’s intrinsic motivation. A cluster-randomized trial examined children’s acceptance of a disliked vegetable over 12 daily taste exposures. These exposures were paired with a tangible reward, a social reward, or no reward, and the findings were compared with the results from a no-treatment control condition. Liking and intake of the vegetable were assessed in a free-choice consumption task at preintervention, postintervention, 1 month after intervention, and 3 months after intervention. Liking increased more in the three intervention conditions than in the control condition, and there were no significant differences between the intervention conditions. These effects were maintained at follow-up. Children in both reward conditions increased consumption, and these effects were maintained for 3 months; however, the effects of exposure with no reward became nonsignificant by 3 months. These results indicate that external rewards do not necessarily produce negative effects and may be useful in promoting healthful eating.

Telling Parents Their Child's Weight Status: Psychological Impact of a Weight-Screening Program

OBJECTIVE. This was a descriptive study examining the psychological impact of a school-based, weight-screening intervention that included feedback to parents. METHODS. Children from years 3 and 6 (6–7 and 10–11 years old) in London schools were measured in school, and parents were sent information on the childs weight status. Children and parents completed questionnaires 6 weeks before and 4 weeks after the feedback; 358 children and 287 parents completed both questionnaires. The main outcome measures (parental feeding practices, parental perception of child weight, child body esteem, child eating behavior, and weight-related teasing) were assessed before and after feedback. Qualitative data on health-behavior change and parents’ and childrens views of the measurement and feedback process were collected at follow-up. RESULTS. Fifty-one percent of the parents (n = 398) volunteered for child measurements and weight feedback. Feedback was not associated with changes in child feeding among parents of healthy-weight children, but dietary restriction increased in parents of overweight girls. Among healthy-weight children, restrained eating decreased and body esteem increased, but there were no significant changes among the overweight group and no changes in reports of teasing. Perceptions of child overweight did not increase significantly, but 50% of the parents of overweight children reported positive changes in health behaviors. The majority (65%) of parents wanted weight feedback on a regular basis, and most children enjoyed the measuring process. CONCLUSIONS. Weight feedback was acceptable to the majority of parents participating in an “opt-in” measurement and feedback program; adverse effects were minimal for children and parents, even when feedback indicated overweight. However, a minority of participants found it distressing, which highlights the importance of managing the process sensitively, particularly for families with overweight children.

Environmental and individual determinants of core and non-core food and drink intake in preschool-aged children in the United Kingdom

Background/Objectives:Strategies to achieve healthier diets for children are likely to benefit from an understanding of the determinants. We examined environmental and individual predictors of childrens intake of ‘core’ foods (fruit and vegetables) and ‘non-core’ foods (snacks and sweetened beverages). Predictors included parental intake, home availability, parental feeding styles (Encouragement and Monitoring) and childrens food preferences. Based on research with older children, we expected intake of both food types to be associated with maternal intake, core foods to be more associated with childrens preferences and non-core food intake more with the home environment.Subjects/Methods:Primary caregivers (n=434) of children (2–5 years) from preschools and Childrens Centres in London, UK, completed a self-report survey in 2008.Results:Multiple regression analyses indicated childrens fruit intake was associated with maternal fruit intake (B=0.29; P=0.000), childrens liking for fruit (B=0.81; P=0.000) and a Monitoring style of parental feeding (B=0.13; P=0.021). Childrens vegetable intake was similarly associated with maternal intake (B=0.39; P=0.000), childrens liking for vegetables (B=0.77; P=0.000), Encouragement (B=0.19; P=0.021) and Monitoring (B=0.11; P=0.029). Non-core snack intake was associated with maternal intake (B=0.25; P=0.029), Monitoring (B=−0.16; P=0.010), home availability (B=0.10; P=0.022) and television viewing (TV) (B=0.28; P=0.012). Non-core drink intake was associated with maternal intake (B=0.32; P=0.000) and TV (B=0.20; P=0.019).Conclusions:Results indicate commonalities and differences in the predictors of core and non-core food intake, with only maternal intake being important across all types. Effective interventions to improve young childrens diets may need to call on different strategies for different foods.

Increasing food acceptance in the home setting: a randomized controlled trial of parent-administered taste exposure with incentives

BACKGROUND The use of rewards to encourage children to eat healthily is controversial. However, researcher-led interventions have shown that incentives combined with taste exposure can increase both intake and liking. To date, this has not been tested in the home setting. OBJECTIVES The objectives were to test the hypothesis that parent-administered repeated taste exposures to an initially disliked vegetable combined with reward will increase childrens liking and intake and to compare the effects of tangible and social rewards. DESIGN In this randomized controlled trial, families with children aged 3-4 y (n = 173) were randomly assigned to exposure + tangible reward (sticker), exposure + social reward (praise), or no-treatment control conditions after a pretest assessment in which a target vegetable was selected for each child. In the intervention groups, parents offered their children 12 daily tastes of the vegetable, giving either praise or a sticker for tasting. No specific advice was given to the control group. Assessments of intake and liking of the target vegetable were conducted by researchers immediately after the intervention period and 1 and 3 mo later. RESULTS Children who received exposure + tangible rewards increased their intake (P = 0.001) and liking (P = 0.001) of their target vegetable significantly more than did children in the control group. Differences were maintained at the 3-mo follow-up (intake: P = 0.005; liking: P = 0.001). Increases in intake and liking in the exposure + social reward group were not significantly different from the control group. CONCLUSION The findings of this home-based study support parental use of tangible rewards with repeated taste exposures to improve childrens diets. This trial is registered as ISRCTN42922680.

Cluster-randomised trial to evaluate the ‘Change for Life’ mass media/ social marketing campaign in the UK

BackgroundSocial marketing campaigns offer a promising approach to the prevention of childhood obesity. Change4Life (C4L) is a national obesity prevention campaign in England. It included mass media coverage aiming to reframe obesity into a health issue relevant to all and provided the opportunity for parents to complete a brief questionnaire (‘How are the Kids’) and receive personalised feedback about their children’s eating and activity. Print and online C4L resources were available with guidance about healthy eating and physical activity. The study aims were to examine the impact of personalised feedback and print material from the C4L campaign on parents’ attitudes and behaviours about their children’s eating and activity in a community-based cluster-randomised controlled trial.MethodsParents of 5–11 year old children were recruited from 40 primary schools across England. Schools were randomised to intervention or control (‘usual care’). Basic demographic data and brief information about their attitudes to their children’s health were collected. Families in intervention schools were mailed the C4L print materials and the ‘How are the Kids’ questionnaire; those returning the questionnaire were sent personalised feedback and others received generic materials. Outcomes included awareness of C4L, attitudes to the behaviours recommended in C4L, parenting behaviours (monitoring and modelling), and child health behaviours (diet, physical activity and television viewing). Follow-up data were collected from parents by postal questionnaire after six months. Qualitative interviews were carried out with a subset of parents (n = 12).Results3,774 families completed baseline questionnaires and follow-up data were obtained from 1,419 families (37.6%). Awareness was high in both groups at baseline (75%), but increased significantly in the intervention group by follow-up (96% vs. 87%). Few parents (5.2% of the intervention group) returned the questionnaire to get personalised feedback. There were few significant group differences in parental attitudes or parenting and child health behaviours at follow-up. Physical activity was rated as less important in the intervention group, but a significant group-by-socioeconomic status (SES) interaction indicated that this effect was confined to higher SES families. Similar interactions were also seen for physical activity monitoring and child television time; with adverse effects in higher SES families and no change in the lower SES families. Effects were little better in families that completed the questionnaire and received personalised feedback. At interview, acceptability of the intervention was modest, although higher in lower SES families.ConclusionsThe C4L campaign materials achieved increases in awareness of the campaign, but in this sample had little impact on attitudes or behaviour. Low engagement with the intervention appeared a key issue.Trial registration numberCurrent Controlled Trials ISRCTN00791709.

Validation of BIA in Obese Children and Adolescents and Re-evaluation in a Longitudinal Study

Decrease in fat mass (FM) is a one of the aims of pediatric obesity treatment; however, measurement techniques suitable for routine clinical assessment are lacking. The objective of this study was to validate whole‐body bioelectrical impedance analysis (BIA; TANITA BC‐418MA) against the three‐component (3C) model of body composition in obese children and adolescents, and to test the accuracy of our new equations in an independent sample studied longitudinally. A total of 77 white obese subjects (30 males) aged 5–22 years, BMI‐standard deviation score (SDS) 1.6–3.9, had measurements of weight, height (HT), body volume, total body water (TBW), and impedance (Z). FM and fat‐free mass (FFM) were calculated using the 3C model or predicted from TANITA. FFM was predicted from HT2/Z. This equation was then evaluated in 17 other obese children (5 males) aged 9–13 years. Compared to the 3C model, TANITA manufacturers equations overestimated FFM by 2.7 kg (P < 0.001). We derived a new equation: FFM = −2.211 + 1.115 (HT2/Z), with r2 of 0.96, standard error of the estimate 2.3 kg. Use of this equation in the independent sample showed no significant bias in FM or FFM (mean bias 0.5 ± 2.4 kg; P = 0.4), and no significant bias in change in FM or FFM (mean bias 0.2 ± 1.8 kg; P = 0.7), accounting for 58% (P < 0.001) and 55% (P = 0.001) of the change in FM and FFM, respectively. Our derived BIA equation, shown to be reliable for longitudinal assessment in white obese children, will aid routine clinical monitoring of body composition in this population.