Physical activity and dietary intake of children aged 9-11 years and the influence of peers on these behaviours: a 1-year follow-up

The Association of Junk Food Consumption with Preadolescents' Environmental Influences: A School-Based Epidemiological Study in Greece

The aim of the present study was to evaluate the impact of environmental influences on Greek preadolescents' junk food consumption. A cross-sectional study, was conducted among 1718 preadolescents (mean (standard deviation(SD)) age: 11.2(0.8) years old; 54% girls) and their parents, during the school years 2014-2016. Parental and child characteristics were collected anonymously, through self-administered and validated questionnaires. Among others, junk food consumption was recorded, classifying children as low, moderate, and high consumers. The majority of the preadolescents were classified as at least moderate junk food consumers, while almost 3/10 children were classified as high junk food consumers. A significantly lower junk food consumption was observed among preadolescents with a healthier family environment, consisting of normal-weight parents who consume junk foods less frequently, prefer home-cooked meals and adhere more to the Mediterranean diet, while more frequent family meals were also associated with lower junk food consumption. In addition, influence from teachers and participation in extracurricular sports activities were significantly associated with lower junk food consumption, while advertisements were found to have a significant negative impact on preadolescents' eating habits. Notwithstanding, peers were not found to influence their dietary choices in terms of junk food consumption. Both parents and teachers seem to be positive influencers on preadolescents' low junk food consumption. The detrimental role of advertisements on junk food consumption is reconfirmed, while peers' influence is not significant on junk food consumption. The need for urgent public health initiatives for the promotion of healthy dietary habits among preadolescents is warranted.

Prediction Model for Physical Activity Level in Primary School Students

The aim of this study was to provide an explanatory prediction model for physical activity level in children, involving a number of influencing variables. In total, 1971 people participated in the study: 657 primary school students and their respective fathers and mothers from 15 schools of Galicia (Spain). The International Questionnaire on Physical Education, Health and Lifestyle was administered. The findings revealed that school year, sex, physical perceived competence and sport practice with friends had a statistically significant relationship on physical activity index. By contrast, the association between the weekly participation of fathers or mothers in sports in the practice of children could not be confirmed. Sport practice with friends was the main predicting variable for physical activity level. Physical perceived competence showed great relevance as well. This knowledge could be of interest to help increase adherence to practice and preventing withdrawal, helping students to stay active and acquire healthy habits for the future.

Designing an adolescent physical activity and nutrition intervention before and after COVID-19: A formative research study

BACKGROUND

With rates of childhood obesity continually increasing, effective physical activity (PA) and nutrition interventions are needed. Formative research is used to tailor interventions to different cultural and geographic contexts and can also be vital in adapting intervention strategies in the face of significant disruptive circumstances (like COVID-19).

OBJECTIVE

We conducted formative research via in-person and online focus groups among middle schoolers and parents to better understand barriers and facilitators to PA and fruit and vegetable (FV) consumption and inform the design of a large intervention for a low-income, urban setting in the U.S. Midwest.

METHODS

We conducted two phases of qualitative focus groups with parents (n=20) and 6-9 grade middle schoolers (n=22). Phase 1 was conducted prior to the COVID-19 pandemic in late 2019, and phase 2 was conducted during the COVID-19 pandemic in the summer of 2020. Focus groups were transcribed and thematically coded using Dedoose software.

RESULTS

Main facilitators to PA prior to the pandemic included the opportunity to have fun, peer influence, competition (for some), and incentives, while main barriers to PA were time constraints and social discomfort. Main facilitators to eating FV included parental influence, preparation technique, and convenience, while barriers included dislike of vegetables, time constraints, and preparation or freshness. During the pandemic, facilitators to PA remained the same, while additional barriers to PA such as lack of motivation and limited time spent outside of the home were reported during the pandemic. For FV consumption, both facilitators and barriers remained the same for both time periods. Additionally, for some participants, the pandemic offered an opportunity to offer more FV to middle schoolers throughout the day.

CONCLUSIONS

Some themes identified were common to those reported in previous studies, such as peer influence on PA and parental influence on FV consumption. Novel themes, such as lack of motivation to be active and limited time outside the home, helped improve intervention adaptation, specifically during the COVID-19 pandemic. The continuity of formative research after a major, unexpected change in intervention context can be essential in targeting areas of an intervention that can be retained and those that need to be adjusted.

CLINICALTRIAL

Early Adolescents' Food Selection After Evaluating the Healthiness of Remote Peers' Food Choices

This study investigates whether asking early adolescents to evaluate the food choices of remote peers improves their own food selection. Participants were students from fifth (N = 219, M_age  = 9.30 years) and sixth grades (N = 248, M_age  = 10.28 years) of varying nationalities living in the United Arab Emirates (race and ethnicity were not collected). Students saw peers' healthy or unhealthy food choices before picking their own food. In some conditions, students also critically evaluated the healthiness of the peers' choices. Evaluation of peer choices led to healthier decisions (d = .53) to the point that it offsets the negative impact of observing unhealthy peer choices. This effect is larger for sixth graders compared to fifth graders.

Preadolescents' healthy eating behavior: peeping through the social norms approach

BACKGROUND

The rising childhood obesity rate is a major public health challenge. The objective of this study is to examine key underlying mechanisms for peer-related social influence on preadolescents' healthy eating behavior by including factors closely linked with the quality of preadolescents' relationship with peers.

METHODS

A cross-sectional study was conducted in a convenience sample of 278 Lithuanian preadolescents, recruited from a public school. A questionnaire containing sociodemographic questions, questions about food intake, peer-related social norms of healthy eating, social self-efficacy, vegetable preference, need for peer approval and feeling of belonging were applied. Data was analyzed using structural equation modeling.

RESULTS

The results of the SEM showed that social self-efficacy predicts feeling of belonging to the peer group and need for peer approval. Feeling of belonging and need for peer approval predict actual intake of vegetables via injunctive norms of healthy eating. However, neither feeling of belonging nor need for peer approval predicted descriptive norms of healthy eating. Contrary to our expectations, descriptive norms were found to be unrelated with actual intake of vegetables, though vegetable preference predicted actual intake of vegetables. Vegetable preference was not predicted by injunctive or descriptive peers' social norms of healthy eating.

CONCLUSIONS

The findings of this study offer insight for informing parents, teachers and for social norms marketing interventions by stressing the importance of social relations when the aim is to encourage healthy eating among preadolescents.

Depletion of Blautia Species in the Microbiota of Obese Children Relates to Intestinal Inflammation and Metabolic Phenotype Worsening

Child obesity constitutes a risk factor for developing insulin resistance which, if sustained, could lead to more severe conditions like type 2 diabetes (T2D) in adulthood. Our study identified previously unknown species whose depletion (Blautia luti and Blautia wexlerae) is associated with insulin resistance in obese individuals. Our results also indicate that these bacterial species might help to reduce inflammation causally linked to obesity-related complications. Childhood is considered a window of opportunity to tackle obesity. These new findings provide, therefore, valuable information for the future design of microbiota-based strategies for the early prevention of obesity-related complications.

Cross-sectional studies conducted with obese and control subjects have suggested associations between gut microbiota alterations and obesity, but the links with specific disease phenotypes and proofs of causality are still scarce. The present study aimed to profile the gut microbiota of lean and obese children with and without insulin resistance to characterize associations with specific obesity-related complications and understand the role played in metabolic inflammation. Through massive sequencing of 16S rRNA gene amplicons and data analysis using a novel permutation approach, we have detected decreased incidence of Blautia species, especially Blautia luti and B. wexlerae, in the gut microbiota of obese children, which was even more pronounced in cases with both obesity and insulin resistance. There was also a parallel increase in proinflammatory cytokines and chemokines (gamma interferon [IFN-γ], tumor necrosis factor alpha [TNF-α], and monocyte chemoattractant protein 1 [MCP-1]) in feces of obese children compared to those of lean ones. B. luti and B. wexlerae were also shown to exert an anti-inflammatory effect in peripheral blood mononuclear cell cultures in vitro, compared to non-obesity-associated species. We suggest that the depletion of B. luti and B. wexlerae species in the gut ecosystem may occur in cases of obesity and contribute to metabolic inflammation leading to insulin resistance.

IMPORTANCE Child obesity constitutes a risk factor for developing insulin resistance which, if sustained, could lead to more severe conditions like type 2 diabetes (T2D) in adulthood. Our study identified previously unknown species whose depletion (Blautia luti and Blautia wexlerae) is associated with insulin resistance in obese individuals. Our results also indicate that these bacterial species might help to reduce inflammation causally linked to obesity-related complications. Childhood is considered a window of opportunity to tackle obesity. These new findings provide, therefore, valuable information for the future design of microbiota-based strategies for the early prevention of obesity-related complications.

Reproducibility and relative validity of a semiquantitative food frequency questionnaire in European preschoolers: The ToyBox study

OBJECTIVES

The aim of this study was to examine the reproducibility and relative validity of a semiquantitative food frequency questionnaire (FFQ) in assessing food group estimates.

METHODS

Food group estimates were assessed via a 37-item FFQ and a 3-d food record (FR). Pearson's correlation coefficients for log-transformed values were calculated to assess the reproducibility and Spearman's rank correlation coefficients for log-transformed values were calculated to assess the validity. Kindergartens from six European countries participated in the preparatory substudies of the ToyBox intervention study; data from preschool children 4 to 6 y of age (n = 196, reproducibility study; n = 324, validation study) were obtained.

RESULTS

In the reproducibility study, positive Pearson's correlation coefficients for single and aggregated food groups ranged from 0.14 for pasta and rice to 0.90 for cooked vegetables. In the validation study, the FR gave higher estimates of 40 of the 50 food items (single and aggregated) examined compared with those obtained from the FFQ. Positive crude Spearman rank correlation coefficients ranged from 0.01 for total beverages (added sugar) and rice to 0.62 for tea. Corrections for the deattenuation effect did not improve observed correlations. Quartiles and tertiles were calculated for a small number of food groups (N = 14) owing to zero consumption in the rest of the groups.

CONCLUSIONS

Moderately good reproducibility and low-moderate relative validity of the FFQ used in preschool children was observed. Relative validity, however, varied by food and beverage group; for some of the "key" foods/drinks targeted in the ToyBox intervention (e.g., biscuits), the validity was good. The findings should be considered in future epidemiologic and intervention studies in preschool children.

Roommate effects in health outcomes

We use randomized roommate assignment in dormitories in a college in Kolkata in India to examine peer effects in weight gains among roommates. We use administrative data on weight, height, and test scores of students at the time of college admission and then survey these students at the end of their first and second years in college. We do not find any significant roommate specific peer effect in weight gain. Our results rather suggest that an obese roommate reduces the probability that the other roommates become obese in subsequent years. We examine potential mechanism using survey data on students' eating habits, smoking, exercise, and sleeping patterns. We find that obese roommates sleep longer, which in turn improves the sleep pattern of others, which might explain the weak negative effect of obese roommates on the weight of others in the same room.

A Multi-omics Approach to Unraveling the Microbiome-Mediated Effects of Arabinoxylan Oligosaccharides in Overweight Humans

The use of dietary fiber food supplementation as a strategy to reduce the burden of diet-related diseases is a matter of study given its cost-effectiveness and the positive results demonstrated in clinical trials. This multi-omics assessment, on different biological samples of overweight subjects with signs of metabolic syndrome, sheds light on the early and less evident effects of short-term AXOS intake on intestinal microbiota and host metabolism. We observed a deep influence of AXOS on gut microbiota beyond their recognized bifidogenic effect by boosting concomitantly a wide diversity of butyrate producers and Prevotella copri, a microbial species abundant in non-Westernized populations with traditional lifestyle and diets enriched in fresh unprocessed foods. A comprehensive evaluation of hundreds of metabolites unveiled new benefits of the AXOS intake, such as reducing the plasma ceramide levels. Globally, we observed that multiple effects of AXOS consumption seem to converge in reversing the glucose homeostasis impairment.

Long-term consumption of dietary fiber is generally considered beneficial for weight management and metabolic health, but the results of interventions vary greatly depending on the type of dietary fibers involved. This study provides a comprehensive evaluation of the effects of a specific dietary fiber consisting of a wheat-bran extract enriched in arabinoxylan-oligosaccharides (AXOS) in a human intervention trial. An integrated multi-omics analysis has been carried out to evaluate the effects of an intervention trial with an AXOS-enriched diet in overweight individuals with indices of metabolic syndrome. Microbiome analyses were performed by shotgun DNA sequencing in feces; in-depth metabolomics using nuclear magnetic resonance in fecal, urine, and plasma samples; and massive lipid profiling using mass spectrometry in fecal and serum/plasma samples. In addition to their bifidogenic effect, we observed that AXOS boost the proportion of Prevotella species. Metagenome analysis showed increases in the presence of bacterial genes involved in vitamin/cofactor production, glycan metabolism, and neurotransmitter biosynthesis as a result of AXOS intake. Furthermore, lipidomics analysis revealed reductions in plasma ceramide levels. Finally, we observed associations between Prevotella abundance and short-chain fatty acids (SCFAs) and succinate concentration in feces and identified a potential protective role of Eubacterium rectale against metabolic disease given that its abundance was positively associated with plasma phosphatidylcholine levels, thus hypothetically reducing bioavailability of choline for methylamine biosynthesis. The metagenomics, lipidomics, and metabolomics data integration indicates that sustained consumption of AXOS orchestrates a wide variety of changes in the gut microbiome and the host metabolism that collectively would impact on glucose homeostasis. (This study has been registered at ClinicalTrials.gov under identifier NCT02215343.)

IMPORTANCE The use of dietary fiber food supplementation as a strategy to reduce the burden of diet-related diseases is a matter of study given its cost-effectiveness and the positive results demonstrated in clinical trials. This multi-omics assessment, on different biological samples of overweight subjects with signs of metabolic syndrome, sheds light on the early and less evident effects of short-term AXOS intake on intestinal microbiota and host metabolism. We observed a deep influence of AXOS on gut microbiota beyond their recognized bifidogenic effect by boosting concomitantly a wide diversity of butyrate producers and Prevotella copri, a microbial species abundant in non-Westernized populations with traditional lifestyle and diets enriched in fresh unprocessed foods. A comprehensive evaluation of hundreds of metabolites unveiled new benefits of the AXOS intake, such as reducing the plasma ceramide levels. Globally, we observed that multiple effects of AXOS consumption seem to converge in reversing the glucose homeostasis impairment.

Towards microbiome-informed dietary recommendations for promoting metabolic and mental health: Opinion papers of the MyNewGut project

The gut microbiota coexists in partnership with the human host through adaptations to environmental and physiological changes that help maintain dynamic homeostatic healthy states. Break-down of this delicate balance under sustained exposure to stressors (e.g. unhealthy diets) can, however, contribute to the onset of disease. Diet is a key modifiable environmental factor that modulates the gut microbiota and its metabolic capacities that, in turn, could impact human physiology. On this basis, the diet and the gut microbiota could act as synergistic forces that provide resilience against disease or that speed the progress from health to disease states. Associations between unhealthy dietary patterns, non-communicable diseases and intestinal dysbiosis can be explained by this hypothesis. Translational studies showing that dietary-induced alterations in microbial communities recapitulate some of the pathological features of the original host further support this notion. In this introductory paper by the European project MyNewGut, we briefly summarize the investigations conducted to better understand the role of dietary patterns and food components in metabolic and mental health and the specificities of the microbiome-mediating mechanisms. We also discuss how advances in the understanding of the microbiome's role in dietary health effects can help to provide acceptable scientific grounds on which to base dietary advice for promoting healthy living.

Effects of total fat intake on bodyweight in children

BACKGROUND

As part of efforts to prevent childhood overweight and obesity, we need to understand the relationship between total fat intake and body fatness in generally healthy children.

OBJECTIVES

To assess the effects and associations of total fat intake on measures of weight and body fatness in children and young people not aiming to lose weight.

SEARCH METHODS

For this update we revised the previous search strategy and ran it over all years in the Cochrane Library, MEDLINE (Ovid), MEDLINE (PubMed), and Embase (Ovid) (current to 23 May 2017). No language and publication status limits were applied. We searched the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov for ongoing and unpublished studies (5 June 2017).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in children aged 24 months to 18 years, with or without risk factors for cardiovascular disease, randomised to a lower fat (30% or less of total energy (TE)) versus usual or moderate-fat diet (greater than 30%TE), without the intention to reduce weight, and assessed a measure of weight or body fatness after at least six months. We included prospective cohort studies if they related baseline total fat intake to weight or body fatness at least 12 months later.

DATA COLLECTION AND ANALYSIS

We extracted data on participants, interventions or exposures, controls and outcomes, and trial or cohort quality characteristics, as well as data on potential effect modifiers, and assessed risk of bias for all included studies. We extracted body weight and blood lipid levels outcomes at six months, six to 12 months, one to two years, two to five years and more than five years for RCTs; and for cohort studies, at baseline to one year, one to two years, two to five years, five to 10 years and more than 10 years. We planned to perform random-effects meta-analyses with relevant subgrouping, and sensitivity and funnel plot analyses where data allowed.

MAIN RESULTS

We included 24 studies comprising three parallel-group RCTs (n = 1054 randomised) and 21 prospective analytical cohort studies (about 25,059 children completed). Twenty-three studies were conducted in high-income countries. No meta-analyses were possible, since only one RCT reported the same outcome at each time point range for all outcomes, and cohort studies were too heterogeneous to combine.Effects of dietary counselling to reduce total fat intake from RCTsTwo studies recruited children aged between 4 and 11 years and a third recruited children aged 12 to 13 years. Interventions were combinations of individual and group counselling, and education sessions in clinics, schools and homes, delivered by dieticians, nutritionists, behaviourists or trained, supervised teachers. Concerns about imprecision and poor reporting limited our confidence in our findings. In addition, the inclusion of hypercholesteraemic children in two trials raised concerns about applicability.One study of dietary counselling to lower total fat intake found that the intervention may make little or no difference to weight compared with usual diet at 12 months (mean difference (MD) -0.50 kg, 95% confidence interval (CI) -1.78 to 0.78; n = 620; low-quality evidence) and at three years (MD -0.60 kg, 95% CI -2.39 to 1.19; n = 612; low-quality evidence). Education delivered as a classroom curriculum probably decreased BMI in children at 17 months (MD -1.5 kg/m2, 95% CI -2.45 to -0.55; 1 RCT; n = 191; moderate-quality evidence). The effects were smaller at longer term follow-up (five years: MD 0 kg/m2, 95% CI -0.63 to 0.63; n = 541; seven years; MD -0.10 kg/m2, 95% CI -0.75 to 0.55; n = 576; low-quality evidence).Dietary counselling probably slightly reduced total cholesterol at 12 months compared to controls (MD -0.15 mmol/L, 95% CI -0.24 to -0.06; 1 RCT; n = 618; moderate-quality evidence), but may make little or no difference over longer time periods. Dietary counselling probably slightly decreased low-density lipoprotein (LDL) cholesterol at 12 months (MD -0.12 mmol/L, 95% CI -0.20 to -0.04; 1 RCT; n = 618, moderate-quality evidence) and at five years (MD -0.09, 95% CI -0.17 to -0.01; 1 RCT; n = 623; moderate-quality evidence), compared to controls. Dietary counselling probably made little or no difference to HDL-C at 12 months (MD -0.03 mmol/L, 95% CI -0.08 to 0.02; 1 RCT; n = 618; moderate-quality evidence), and at five years (MD -0.01 mmol/L, 95% CI -0.06 to 0.04; 1 RCT; n = 522; moderate-quality evidence). Likewise, counselling probably made little or no difference to triglycerides in children at 12 months (MD -0.01 mmol/L, 95% CI -0.08 to 0.06; 1 RCT; n = 618; moderate-quality evidence). Lower versus usual or modified fat intake may make little or no difference to height at seven years (MD -0.60 cm, 95% CI -2.06 to 0.86; 1 RCT; n = 577; low-quality evidence).Associations between total fat intake, weight and body fatness from cohort studiesOver half the cohort analyses that reported on primary outcomes suggested that as total fat intake increases, body fatness measures may move in the same direction. However, heterogeneous methods and reporting across cohort studies, and predominantly very low-quality evidence, made it difficult to draw firm conclusions and true relationships may be substantially different.

AUTHORS' CONCLUSIONS

We were unable to reach firm conclusions. Limited evidence from three trials that randomised children to dietary counselling or education to lower total fat intake (30% or less TE) versus usual or modified fat intake, but with no intention to reduce weight, showed small reductions in body mass index, total- and LDL-cholesterol at some time points with lower fat intake compared to controls. There were no consistent effects on weight, high-density lipoprotein (HDL) cholesterol or height. Associations in cohort studies that related total fat intake to later measures of body fatness in children were inconsistent and the quality of this evidence was mostly very low. Most studies were conducted in high-income countries, and may not be applicable in low- and middle-income settings. High-quality, longer-term studies are needed, that include low- and middle-income settings to look at both possible benefits and harms.

Effects of total fat intake on bodyweight in children

BACKGROUND

As part of efforts to prevent childhood overweight and obesity, we need to understand the relationship between total fat intake and body fatness in generally healthy children.

OBJECTIVES

To assess the effects of total fat intake on measures of weight and body fatness in children and young people not aiming to lose weight.

SEARCH METHODS

For this update we revised the previous search strategy and ran it over all years in the Cochrane Library, MEDLINE (Ovid), MEDLINE (PubMed), and Embase (Ovid) (current to 23 May 2017). No language and publication status limits were applied. We searched the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov for ongoing and unpublished studies (5 June 2017).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in children aged 24 months to 18 years, with or without risk factors for cardiovascular disease, randomised to a lower fat (30% or less of total energy (TE)) versus usual or moderate-fat diet (greater than 30%TE), without the intention to reduce weight, and assessed a measure of weight or body fatness after at least six months. We included prospective analytical cohort studies in these children if they related baseline total fat intake to weight or body fatness at least 12 months later. We duplicated inclusion decisions and resolved disagreement by discussion with other authors.

DATA COLLECTION AND ANALYSIS

We extracted data on participants, interventions or exposures, controls and outcomes, and trial or cohort quality characteristics, as well as data on potential effect modifiers, and assessed risk of bias for all included studies. We extracted outcome data using the following time point ranges, when available: RCTs: baseline to six months, six to 12 months, one to two years, two to five years and more than five years; cohort studies: baseline to one year, one to two years, two to five years, five to 10 years and more than 10 years. We planned to perform random-effects meta-analyses with relevant subgrouping, and sensitivity and funnel plot analyses where data allowed.

MAIN RESULTS

We included 24 studies comprising three parallel-group RCTs (n = 1054 randomised) and 21 prospective analytical cohort studies (about 25,059 children completed). Twenty-three were conducted in high-income countries. No meta-analyses were possible, since only one RCT reported the same outcome at each time point range for all outcomes, and cohort studies were too heterogeneous.For the RCTs, concerns about imprecision and poor reporting limited our confidence in our findings. In addition, the inclusion of hypercholesteraemic children in two trials raised concerns about applicability. Lower versus usual or modified total fat intake may have made little or no difference to weight over a six- to twelve month period (mean difference (MD) -0.50 kg, 95% confidence interval (CI) -1.78 to 0.78; 1 RCT; n = 620; low-quality evidence), nor a two- to five-year period (MD -0.60 kg, 95% CI -2.39 to 1.19; 1 RCT; n = 612; low-quality evidence). Compared to controls, lower total fat intake (30% or less TE) probably decreased BMI in children over a one- to two-year period (MD -1.5 kg/m2, 95% CI -2.45 to -0.55; 1 RCT; n = 191; moderate-quality evidence), with no other differences evident across the other time points (two to five years: MD 0.00 kg/m2, 95% CI -0.63 to 0.63; 1 RCT; n = 541; greater than five years; MD -0.10 kg/m2, 95% CI -0.75 to 0.55; 1 RCT; n = 576; low-quality evidence). Lower fat intake probably slightly reduced total cholesterol over six to 12 months compared to controls (MD -0.15 mmol/L, 95% CI -0.24 to -0.06; 1 RCT; n = 618; moderate-quality evidence), but may make little or no difference over longer time periods. Lower fat intake probably slightly decreased low-density lipoprotein (LDL) cholesterol over six to 12 months (MD -0.12 mmol/L, 95% CI -0.20 to -0.04; 1 RCT; n = 618, moderate-quality evidence) and over two to five years (MD -0.09, 95% CI -0.17 to -0.01; 1 RCT; n = 623; moderate-quality evidence), compared to controls. However, lower total fat intake probably made little or no difference to HDL-C over a six- to 12-month period (MD -0.03 mmol/L, 95% CI -0.08 to 0.02; 1 RCT; n = 618; moderate-quality evidence), nor a two- to five-year period (MD -0.01 mmol/L, 95% CI -0.06 to 0.04; 1 RCT; n = 522; moderate-quality evidence). Likewise, lower total fat intake probably made little or no difference to triglycerides in children over a six- to 12-month period (MD -0.01 mmol/L, 95% CI -0.08 to 0.06; 1 RCT; n = 618; moderate-quality evidence). Lower versus usual or modified fat intake may make little or no difference to height over more than five years (MD -0.60 cm, 95% CI -2.06 to 0.86; 1 RCT; n = 577; low-quality evidence).Over half the cohort analyses that reported on primary outcomes suggested that as total fat intake increases, body fatness measures may move in the same direction. However, heterogeneous methods and reporting across cohort studies, and predominantly very low-quality evidence, made it difficult to draw firm conclusions and true relationships may be substantially different.

AUTHORS' CONCLUSIONS

We were unable to reach firm conclusions. Limited evidence from three trials that randomised children to a lower total fat intake (30% or less TE) versus usual or modified fat intake, but with no intention to reduce weight, showed small reductions in body mass index, total- and LDL-cholesterol at some time points with lower fat intake compared to controls, and no consistent differences in effects on weight, high-density lipoprotein (HDL) cholesterol or height. Associations in cohort studies that related total fat intake to later measures of body fatness in children were inconsistent and the quality of this evidence was mostly very low. Twenty-three out of 24 included studies were conducted in high-income countries, and may not be applicable in low- and middle-income settings. High-quality, longer-term studies are needed, that include low- and middle-income settings and look at both possible benefits and risks.

Teacher and Friend Social Support: Association with Body Weight in African-American Adolescent Females

The purpose of this study was to examine the direct and indirect ecological influences of teacher and friend social support on body weight and diet behaviors in African-American adolescent females. Using a quantitative, cross-sectional research design, a convenience sample of 182 urban African-American adolescent females (12-17 years old) completed a 39-item questionnaire. The questionnaire assessed perceived teacher social support, friend social support, nutrition self-efficacy, and diet behaviors (with internal reliability values of scale items: alpha = 0.74, 0.81, 0.77, and 0.69 respectively). Anthropometric assessments were conducted to measure height and weight to compute BMI. Majority of the participants were in middle or early high school (65 %) and were overweight or obese (57.7 %). Both teacher social support and friend social support demonstrated a positive, indirect influence on child weight status through nutrition self-efficacy and diet behaviors following two different and specific paths of influence. Diet behaviors, in turn, demonstrated a positive, direct effect on child weight status. In the structural model, teacher social support had the greatest effect on diet behaviors, demonstrating a direct, positive influence on diet behaviors (B = 0.421, p < 0.05), but its direct effect on nutrition self-efficacy was not significant. Friend social support demonstrated a positive, direct effect on nutrition self-efficacy (B = 0.227, p < 0.05), but its direct effect on diet behaviors was not statistically significant. The study's findings call for actively addressing the childhood obesity epidemic in the school environment by implementing health behavior change strategies at various social and ecological environmental levels.

I Eat Healthier Than You: Differences in Healthy and Unhealthy Food Choices for Oneself and for Others

The present study investigated self-other biases in actual eating behavior based on the observation of three different eating situations. To capture the complexity of real life food choices within a well-controlled setting, an ecologically valid fake food buffet with 72 different foods was employed. Sixty participants chose a healthy, a typical, and an unhealthy meal for themselves and for an average peer. We found that the typical meal for the self was more similar to the healthy than to the unhealthy meal in terms of energy content: The mean difference between the typical and healthy meals was MΔ = 1368 kJ (327 kcal) as compared to a mean difference between the typical and unhealthy meals of MΔ = 3075 kJ (735 kcal). Moreover, there was evidence that people apply asymmetrical standards for themselves and others: Participants chose more energy for a peer than for themselves (M = 4983 kJ or 1191 kcal on average for the peers' meals vs. M = 3929 kJ or 939 kcal on average for the own meals) and more high-caloric food items for a typical meal, indicating a self-other bias. This comparatively positive self-view is in stark contrast to epidemiological data indicating overall unhealthy eating habits and demands further examination of its consequences for behavior change.

The effect of a peer on VO2 and game choice in 6-10 year old children

Relative to sedentary video games (e.g., Playstation 2®), playing physically active video games (e.g., Nintendo Wii Sports Boxing®) significantly increases caloric expenditure in children. Studies have demonstrated that the presence of a peer increases physical activity in children. We sought to determine if children would expend more energy and find playing the “exergame” (Wii) more motivating than the sedentary video game (Playstation 2) when with a peer. Seventeen children (age 8.5 ± 0.4 years) rested, played the sedentary video game and “exergame” for 10 min each, in two conditions: one in which the children rested/played the games alone (alone condition) and another in which they played with a peer (peer condition). Oxygen consumption (VO₂), and liking (visual analog scale) was assessed for each 10-min condition. After three 10-min resting/gaming conditions, motivation was assessed using a relative reinforcing value task in which children performed computer mouse presses to gain additional access for either the sedentary video game or “exergame.” VO₂ was greater (p < 0.001) during “exergame” play (mean = 12.17 ± 4.1 ml·kg⁻¹·min⁻¹) vs. rest (mean = 5.14 ± 1.46 ml·kg⁻¹·min⁻¹) and the sedentary video game (mean = 5.83 ± 2.1 ml·kg⁻¹·min⁻¹). During the peer condition, there were no significant differences (p > 0.05) in VO₂ relative to the alone condition. In an exploratory analysis boys exhibited a greater (p = 0.02) increase in VO₂ from rest to “exergame” (Δ 9.0 ± 3.7 ml·kg⁻¹·min⁻¹), relative to girls (Δ 4.9 ± 2.9 ml·kg⁻¹·min⁻¹). Boys showed a significantly greater increase (p = 0.05) in VO₂ from the resting condition to “exergame” in the presence of a peer (Δ 11.1 ± 5.3 ml·kg⁻¹·min⁻¹) vs. the alone condition (Δ 6.8 ± 3.1 ml·kg⁻¹ ·min⁻¹). Liking was significantly (p < 0.001) greater for “exergame” (7.7 ± 1.9 cm) and the sedentary video game (8.3 ± 1.3 cm) relative to rest (4.0 ± 2.8 cm). Motivation for “exergame” significantly decreased (p = 0.03) from alone (340.8 ± 106.8 presses) to the peer condition (147.8 ± 81.6 presses).

Conclusion: VO₂ was greater during “exergame” play relative to the sedentary video game. The presence of a peer did not increase VO₂ during “exergame” play. Surprisingly, the presence of a peer decreased children's motivation to play “exergame” vs. the sedentary video game.

Peer mentoring is associated with positive change in physical activity and aerobic fitness of grades 4, 5, and 6 students in the heart healthy kids program

Only 7% of Canadian children achieve activity recommendations, contributing to obesity and preventable disease. The Heart Healthy Kids (H2K) program was designed to test the relationship between peer mentoring, physical activity, and cardiovascular fitness. Participants from 10 schools (5 control, 5 intervention) were enrolled in the program. In control schools, H2K included a physical activity challenge and education sessions. Intervention schools included the addition of a peer-mentoring component. Physical activity was measured through daily pedometer recording. Cardiovascular fitness was evaluated using the PACER (Progressive Aerobic Cardiovascular Endurance Run) protocol to calculate maximal oxygen uptake (VO2 max). Participants included 808 children (average age 9.9 ± 1.0 years). Although control and intervention schools did not differ at baseline, participants with peer mentoring logged significantly more steps per school day, on average, than those in control schools (6,785 ± 3,011 vs. 5,630 ± 2,586; p < .001). Male participants logged significantly more steps per school day than female participants. A significant improvement in VO2 max was also noted in intervention schools, with an average increase of 1.72 ml/mg/min. H2K was associated with positive change in physical activity and cardiovascular fitness, suggesting that peer mentoring shows promise for application in health promotion interventions.

An assessment of health behavior peer effects in Peking University dormitories: a randomized cluster-assignment design for interference

Background

Relatively little is known about the peer influence in health behaviors within university dormitory rooms. Moreover, in China, the problem of unhealthy behaviors among university students has not yet been sufficiently recognized. We thus investigated health behavior peer influence in Peking University dormitories utilizing a randomized cluster-assignment design.

Methods

Study design: Cross-sectional in-dormitory survey. Study population: Current students from Peking University Health Science Center from April to June, 2009. Measurement: Self-reported questionnaire on health behaviors: physical activity (including bicycling), dietary intake and tobacco use.

Results

Use of bicycle, moderate-intensity exercise, frequency of sweet food and soybean milk intake, frequency of roasted/baked/toasted food intake were behaviors significantly or marginally significantly affected by peer influence.

Conclusion

Health behavior peer effects exist within dormitory rooms among university students. This could provide guidance on room assignment, or inform intervention programs. Examining these may demand attention from university administrators and policy makers.

Influence of friends on children's physical activity: a review

We examined evidence for friendship influences on children's physical activity (PA) through systematic searches of online databases in May 2012. We identified 106 studies (25 qualitative) published in English since 2000 that analyzed indicators of friendship influences (e.g., communication about PA, friends' PA, and PA with friends) among persons younger than 19 years. Children's PA was positively associated with encouragement from friends (43 of 55 studies indicating a positive relationship), friends' own PA (30/35), and engagement with friends in PA (9/10). These findings are consistent with friends influencing PA, but most studies did not isolate influence from other factors that could explain similarity. Understanding friendship influences in childhood can facilitate the promotion of lifelong healthy habits. PA with friends should be considered in health promotion programs.

Psychosocial correlates of physical activity in school children aged 8-10 years

BACKGROUND

Understanding correlates of physical activity (PA) among children in different populations may contribute to fostering active lifestyles. This study considered gender differences in relationships between biologic (body mass index, BMI), demographic (socioeconomic sport status, SES) and psychosocial correlates of PA and level of PA in Portuguese primary school children.

METHODS

683 children, aged 8-10 years, from 20 different elementary schools in northern Portugal were surveyed. Weight status was classified using International Obesity Task Force (IOTF) criteria for the BMI. Family SES was estimated from school records. PA level and psychosocial correlates (attraction to PA, perceived physical competence and parental socialization) were obtained with interview and standardized questionnaires, respectively. Sex-specific hierarchical multiple regression analyses (SPSS 18.0) were conducted and included two blocks of predictor variables (biologic and demographic, and psychosocial).

RESULTS

Level of PA was significantly higher in boys than girls. Enjoyment of participation in vigorous PA was positively associated with level of PA. Perceived acceptance by peers in games and sports and parental encouragement were positively and significantly related to PA in girls. Perceived physical competence was positively and significantly related to PA in boys. Weight status and SES were not associated with PA.

CONCLUSIONS

Boys and girls differed in perceived attractiveness of PA and perceived physical competence, both of which influenced level of PA. Differences in perceptions may be important aspects of motivation for PA in school children.

Assessment tools of energy balance-related behaviours used in European obesity prevention strategies: review of studies during preschool

Valid and reliable measures of energy balance-related behaviours are required when evaluating the effectiveness of public health interventions aiming at prevention of childhood obesity. A structured descriptive review was performed to appraise food intake, physical activity and sedentary behaviour assessment tools used in obesity intervention strategies targeting mainly preschool children across Europe. In total, 25 papers are described, addressing energy balance-related behaviours as study outcomes and targeting individuals or clusters of individuals at school- or home-based environment. Parentally reported food records and 24-h recalls were commonly used to assess food intake. Subjective levels of physical activity and sedentary behaviour were commonly accessed via parentally reported questionnaires. Accelerometry was used to obtain objective measures of physical activity. Insufficient evidence of tool evaluation was provided. When feasible, food records and accelerometry are recommended as the most appropriate methods to assess food intake in young children. Sedentary behaviour could be assessed via questionnaires that include key indicators of sedentarism and are able to differentiate individual practices. The choice of methodology for the assessment of specific intervention effects should be equally balanced between required accuracy levels and feasibility, and be guided by the intervention targets.

Do peers matter? A review of peer and/or friends' influence on physical activity among American adolescents

This systematic review investigated the relationship between peer and/or friend variables and physical activity among adolescents by synthesising cross-sectional, longitudinal, and experimental research conducted in the US. Seven electronic databases were searched to identify related articles published within the last 10 years and the articles reviewed included adolescents between 10 and 18 years. Studies reporting a measure of physical activity for adolescents and at least one potential peer and/or friend variable were included. Research demonstrated that peers and friends have an important role to play in the physical activity behavior of adolescents. Six processes were identified through which peers and/or friends may have an influence on physical activity including: peer and/or friend support, presence of peers and friends, peer norms, friendship quality and acceptance, peer crowds, and peer victimization. The theoretical significance of these results is assessed and the development of peer-related physical activity programs for adolescents is discussed.

Beverage consumption and BMI of British schoolchildren aged 9-13 years

OBJECTIVE

Adequate fluid intake has been well documented as important for health but whether it has adverse effects on overall energy and sugar intakes remains under debate. Many dietary studies continue to refrain from reporting on beverage consumption, which the present study aimed to address.

DESIGN

A cross-sectional survey investigated self-reported measures of dietary intake and anthropometric measurements.

SETTING

Primary and secondary schools in south-west London, UK.

SUBJECTS

Boys and girls (n 248) aged 9–13 years.

RESULTS

Boys consumed 10 % and girls consumed 9 % of their daily energy intake from beverages and most children had total sugar intakes greater than recommended. Beverages contributed between a quarter and a third of all sugars consumed, with boys aged 11–13 years consuming 32 % of their total sugar from beverages. There was a strong relationship between consumption of beverages and energy intake; however, there was no relationship between beverage type and either BMI or BMI Z-score. Fruit juices and smoothies were consumed most frequently by all girls and 9–10-year-old boys; boys aged 11–13 years preferred soft drinks and consumed more of their daily energy from soft drinks. Milk and plain water as beverages were less popular.

CONCLUSIONS

Although current health promotion campaigns in schools merit the attention being given to improving hydration and reducing soft drinks consumption, it may be also important to educate children on the energy and sugar contents of all beverages. These include soft drinks, as well as fruit juices and smoothies, which are both popular and consumed regularly.

Dietary patterns and breast-feeding in Australian children

OBJECTIVE

To determine the dietary patterns of a national sample of 2-8-year-old Australian children and to establish whether breast-feeding is associated with dietary patterns in this age group.

DESIGN

Cross-sectional study using 24 h recall data from the 2007 Australian National Children's Nutrition and Physical Activity Survey.

SETTING

Australia.

SUBJECTS

A total of 2287 children aged 2-8 years.

RESULTS

Principal component factor analysis identified three distinct patterns. The 'Non-core food groups' pattern included food groups such as whole-fat dairy products, cheese, medium-high sugar-sweetened breakfast cereals and sweet biscuits, no fruit, reduced/low-fat dairy products and wholegrain bread/rolls. The 'Healthy, meat and vegetable' pattern included vegetables, red meat, fruit and wholegrain bread/rolls and was inversely associated with take-away foods and carbonated sugar-sweetened beverages. The 'Combination' pattern contained many food groups including candy (not chocolate based), pasta/rice products, nuts/seeds, cakes and chocolate, but no fruit or vegetables. Of the 2287 children, 2064 (89·3 %) had been breast-fed. A positive association was found between breast-feeding and the healthy, meat and vegetable pattern (r = 0·267) but not with the other two patterns. Higher scores on this pattern were also associated with younger age, lower BMI, higher birth weight, high likelihood of being in the less-disadvantaged Socio-economic Indexes for Areas category and less likelihood of the child's parents having a lower educational level.

CONCLUSIONS

These results provide suggestive evidence that breast-feeding during infancy is associated with a healthy dietary pattern in childhood and offers a likely pathway to explain the previously reported association between breast-feeding and chronic disease.

Body mass, frequency of eating and breakfast consumption in 9-13-year-olds

BACKGROUND

Unhealthy eating patterns in childhood can lead to adverse health conditions, particularly obesity. However, debate remains around the precise eating behaviours that lead to these conditions. The present study aimed to address this lack of evidence by reporting on the eating frequency, breakfast consumption and body mass index (BMI, kg m(-2) ) of youth in the UK.

METHODS

A total of 264 (133 boys and 131 girls) participants, aged 10-13years, completed self-report measures of dietary intake via 3-day food/drink diaries (Friday to Sunday). Trained researchers recorded height and weight to calculate the BMI. Diaries were analysed using dietplan 6 nutritional analysis software (Forestfield Software, Horsham, UK) and multivariate linear regression was used to examine any association between breakfast consumption, frequency of eating and BMI.

RESULTS

No relationship existed between BMI Z-score, eating frequency and breakfast consumption. However, frequent breakfast consumers had significantly lower mean (SD) BMI Z-scores [0.18(1.06) versus 0.57(1.23)] and higher intakes of iron, calcium and vitamin E than those who did not eat breakfast regularly. Those aged ≥11years consumed breakfast less frequently [0.92(0.20)] and were less likely to eat regularly [4.6(1.4)] than those aged ≤10years.

CONCLUSIONS

Older boys were the least likely to eat regularly and the least likely to consume breakfast. Promoting the importance of regular eating, particularly breakfast consumption to these boys, may be essential to ensure healthier, long-term eating patterns. Furthermore, the lower breakfast intakes in 11-13-year-olds and higher BMI Z-scores of those who did not eat breakfast regularly should be monitored.