Dieting status influences associations between dietary patterns and body composition in adolescents: a cross-sectional study

Associations between dietary intake and physical activity, as behavioral indicators, with body fat in adolescents from Mexico

Introduction

Introduction: the prevention of cardiometabolic diseases is currently a priority due to its relationship with COVID-19 complications. Unhealthy lifestyles, like inadequate diet and physical inactivity, are the cornerstone for obesity and cardiometabolic risk. Objective: to examine the association between diet and physical activity with body fat in Mexican adolescents. Methods: the study was cross-sectional. Data included socio-demographic variables, health history and smoking habit obtained through questionnaires; blood pressure and anthropometry measurements; food and nutrient intake through 24-hour recalls; and physical activities through the International Physical Activity Questionnaire (IPAQ). Univariate analyses were used and multiple models were built by stepwise forward selection (p ≤ 0.05 and biological plausibility). Results: participants were n = 230 students, 18.5 ± 0.4 years and 54.8 % men. Three models associated with body fat were obtained. In the first model, saturated fatty acids (β = 0.30, p = 0.028) were significant positive associated, while vigorous physical activity was significant negative associated as a protective factor (β = -0.007, p = 0.023). In the second model, total fat (β = 0.17, p = 0.005) was significant positive associated, and vigorous physical activity was significant negative associated (β = -0.007, p = 0.023). The third model included fruits and vegetables (β = -5.49, p = 0.092) and vigorous physical activity (β = -0.006, p = 0.058) as protective factors. Conclusions: dietary intake of total fat and saturated fatty acids, and vigorous physical activity, were significantly associated with body fat, while fruits and vegetables trended toward significance, in Mexican adolescents. Community-based programs that promote intake of protective foods and reduction of risky foods, and encourage vigorous physical activity, are needed in adolescents.

Smartphone camera based assessment of adiposity: a validation study

Body composition is a key component of health in both individuals and populations, and excess adiposity is associated with an increased risk of developing chronic diseases. Body mass index (BMI) and other clinical or commercially available tools for quantifying body fat (BF) such as DXA, MRI, CT, and photonic scanners (3DPS) are often inaccurate, cost prohibitive, or cumbersome to use. The aim of the current study was to evaluate the performance of a novel automated computer vision method, visual body composition (VBC), that uses two-dimensional photographs captured via a conventional smartphone camera to estimate percentage total body fat (%BF). The VBC algorithm is based on a state-of-the-art convolutional neural network (CNN). The hypothesis is that VBC yields better accuracy than other consumer-grade fat measurements devices. 134 healthy adults ranging in age (21-76 years), sex (61.2% women), race (60.4% White; 23.9% Black), and body mass index (BMI, 18.5-51.6 kg/m2) were evaluated at two clinical sites (N = 64 at MGH, N = 70 at PBRC). Each participant had %BF measured with VBC, three consumer and two professional bioimpedance analysis (BIA) systems. The PBRC participants also had air displacement plethysmography (ADP) measured. %BF measured by dual-energy x-ray absorptiometry (DXA) was set as the reference against which all other %BF measurements were compared. To test our scientific hypothesis we run multiple, pair-wise Wilcoxon signed rank tests where we compare each competing measurement tool (VBC, BIA, …) with respect to the same ground-truth (DXA). Relative to DXA, VBC had the lowest mean absolute error and standard deviation (2.16 ± 1.54%) compared to all of the other evaluated methods (p < 0.05 for all comparisons). %BF measured by VBC also had good concordance with DXA (Lin's concordance correlation coefficient, CCC: all 0.96; women 0.93; men 0.94), whereas BMI had very poor concordance (CCC: all 0.45; women 0.40; men 0.74). Bland-Altman analysis of VBC revealed the tightest limits of agreement (LOA) and absence of significant bias relative to DXA (bias -0.42%, R2 = 0.03; p = 0.062; LOA -5.5% to +4.7%), whereas all other evaluated methods had significant (p < 0.01) bias and wider limits of agreement. Bias in Bland-Altman analyses is defined as the discordance between the y = 0 axis and the regressed line computed from the data in the plot. In this first validation study of a novel, accessible, and easy-to-use system, VBC body fat estimates were accurate and without significant bias compared to DXA as the reference; VBC performance exceeded those of all other BIA and ADP methods evaluated. The wide availability of smartphones suggests that the VBC method for evaluating %BF could play an important role in quantifying adiposity levels in a wide range of settings.Trial registration: ClinicalTrials.gov Identifier: NCT04854421.

Association between dietary patterns and body composition in normal-weight subjects with metabolic syndrome

Background and aims

The development of metabolic syndrome (MetS) has been proposed to be related to dietary pattern and body compostion indexes. Diet is one of the most important lifestyle-related factors which may regulate the inflammatory process. Numerous individual foods and dietary patterns can have a valuable health effect that is associated with their anti-inflammatory properties. Here we aimed to investigate the association between body composition indexes and dietary patterns in individuals with metabolic syndrome who were nnormal for weight.

Methods and materials

Normal weight subjects with MetS were recruited as part of Survey of Ultraviolet Intake by Nutritional Approach (SUVINA). A validated food frequency questionnaire (FFQ) was used to determine dietary patterns that were: low-, or high in antioxidant; dietary inflammation index (DII) and health eating index (HEI) were also determined. Body composition indexes including basal metabolic rate (BMR), body free fat mass (BFFM), body fat mass (BFM), body fat percentage (BFP), trunk fat and total body water (TBW) were measured using a InBody body composition analyser. A P value <0.05 was considered significant.

Results

A total 77 individuals including 29 males and 48 females were recruited into the study. A high-antioxidant dietary pattern was significantly correlated with BMR (p = 0.002), BFFM (p = 0.007) and TBW (p = 0.002). There was no significant relationship between body compostion with a low-antioxidant dietary pattern, DII and HEI. After adjusting for age and sex, our findings showed that a high-antioxidant dietary pattern were independently associated with BMR, BFFM and TBW.

Conclusion

A high-antioxidant dietary pattern was independently associated with decreased BMR, BFFM and TBW, while no association was found between body composition indexes and DII and HEI in normal weight paticipants with MetS.

Breakfast Dietary Pattern Is Inversely Associated with Overweight/Obesity in European Adolescents: The HELENA Study

Obesity in children and adolescents is a public health problem and diet can play a major role in this condition. We aimed to identify sex-specific dietary patterns (DP) and to evaluate the association with overweight/obesity in European adolescents. We conducted a cross-sectional analysis with 2327 adolescents aged between 12.5 to 17.5 years from a multicenter study across Europe. The body mass index was categorized in “normal weight” and “overweight/obesity”. Two non-consecutive 24-h dietary recalls were collected with a computerized self-reported software. Principal component factor analysis was used to identify DP. Mixed-effect logistic regression models were used to evaluate the association between the sex-specific DP and overweight/obesity outcome. As a result, we found three DP in boys (snacking and bread, Mediterranean diet, and breakfast) and four DP in girls (convenience, plant-based and eggs, Western, and breakfast). The association between DP and overweight/obesity highlights that those adolescents with higher adherence to the breakfast DP had lower odds for overweight/obesity, even after the inclusion of covariables in the adjustments. In European adolescents, the breakfast DP positively characterized by breakfast cereals, fruit, milk, and dairy and negatively characterized by sugar-sweetened beverages in boys and negatively characterized by cereals (pasta, rice, and others) in girls, was inversely associated with overweight/obesity.

Association of dietary patterns with blood pressure and body adiposity in adolescents: a systematic review

This paper aimed to systematically review the results of observational studies that investigated the association of dietary patterns with blood pressure and body adiposity markers in adolescents. Articles were searched in July 2020 in PubMed, Scopus, Web of Science, and Scientific Electronic Library Online (SciELO). Of the 3408 studies found, 24 fulfilled the inclusion criteria and were considered in this review. Almost all studies (n = 23) identified at least one unhealthy pattern, predominantly characterized as consumption of confectionery, refined grains, sweets, sweetened drinks, red meats, and processed meats. Fourteen of the twenty-four studies found a significant association between any dietary pattern and blood pressure and/or body adiposity markers. There was a positive association of dietary patterns - characterized by the consumption of foods rich in sodium, animal fat, refined carbohydrates, and low in fiber - with increased blood pressure and body adiposity. Our findings highlight the importance of studies with this scope, whose results can support the surveillance of adolescent's health. However, considering the limited number of studies that found a significant association and their limitations, the present results should be interpreted carefully. More prospective studies are needed to determine how adherence to dietary patterns could influence blood pressure and body adiposity markers in the long term.

Weight Management Efforts, But Not Weight Perceptions, Are Associated with Dietary Quality among Youth and Young Adults in Canada

BACKGROUND

Efforts to lose, gain, or maintain weight are prevalent among youth and young adults, but little is known about the relationship between weight management efforts and dietary quality. Attempts to manage weight are typically driven by weight perceptions, which may also uniquely affect overall diet.

OBJECTIVE

The objective was to explore sex-stratified associations between weight management efforts and perceptions with dietary quality among youth and young adults.

DESIGN

Cross-sectional online survey data were drawn from Wave 1 (2016) of the Canada Food Study.

PARTICIPANTS/SETTING

Youth and young adults (n = 3,000), aged 16 to 30 years, were recruited from community settings in five Canadian cities and completed the online survey. The analytic sample consisted of 2,040 participants.

MAIN OUTCOME MEASURES

The Healthy Eating Index-2015 (HEI-2015) was used to characterize dietary quality among participants who completed a 24-hour recall. Respondents reported their weight change efforts over the past year and their weight perception.

STATISTICAL ANALYSES PERFORMED

Sex-stratified multiple linear regression analyses were conducted to investigate relationships between each of weight management efforts and perceptions, separately, and dietary quality, controlling for known covariates.

RESULTS

The HEI-2015 mean score was 52 of 100 possible points. Nearly one quarter of male and female respondents reported not trying to do anything about their weight, whereas 16% reported trying to maintain, 28% and 5% trying to gain, and 33% and 55% trying to lose weight, respectively. Most respondents (63% of males and 66% of females) perceived their weight as just about right. Among males, trying to gain or maintain weight were each significantly associated with higher HEI-2015 mean scores compared with not trying to manage weight (P < .01 and <.001, respectively), whereas this relationship existed only for weight maintenance among female respondents (P < .01). Weight perceptions and HEI-2015 mean scores were not significantly related.

CONCLUSIONS

Efforts to manage weight, which are commonplace among youth and young adults, are associated with dietary quality. Future behavioral research may provide insights into strategies used by youth to manage weight, guiding interventions that recognize links among weight-related behaviors, dietary quality, and other determinants of health.

Dietary patterns associated with meeting the WHO free sugars intake guidelines

Objective:

Emerging evidence suggests that free sugars intake in many countries exceeds that recommended by the WHO. However, information regarding real-world dietary patterns associated with meeting the WHO free sugars guidelines is lacking. The current study aimed to determine dietary patterns associated with meeting the guidelines to inform effective free sugars reduction interventions in New Zealand (NZ) and similar high-income countries.

Design:

Dietary patterns were derived using principal component analysis on repeat 24-h NZ Adult Nutrition Survey dietary recall data. Associations between dietary patterns and the WHO guidelines (<5 and <10 % total energy intake) were determined using logistic regression analyses.

Setting:

New Zealand.

Participants:

NZ adults (n 4721) over 15 years old.

Results:

Eight dietary patterns were identified: ‘takeaway foods and alcohol’ was associated with meeting both WHO guidelines; ‘contemporary’ was associated with meeting the <10 % guideline (males only); ‘fast foods, sugar-sweetened beverages and dessert’, ‘traditional’ and ‘breakfast foods’ were negatively associated with meeting both guidelines; ‘sandwich’ and ‘snack foods’ were negatively associated with the <5 % guideline; and ‘saturated fats and sugar’ was negatively associated with the <10 % guideline.

Conclusions:

The majority of NZ dietary patterns were not consistent with WHO free sugars guidelines. It is possible to meet the WHO guidelines while consuming a healthier (‘contemporary’) or energy-dense, nutrient-poor (‘takeaway foods and alcohol’) diet. However, the majority of energy-dense patterns were not associated with meeting the guidelines. Future nutrition interventions would benefit from focusing on establishing healthier overall diets and reducing consumption and free sugars content of key foods.

Reproducibility of A Non-Quantitative Food Frequency Questionnaire (62-Item FFQ-6) and PCA-Driven Dietary Pattern Identification in 13-21-Year-Old Females

The aim of this study was to evaluate the test-retest reproducibility of a non-quantitative food frequency questionnaire (acronym: 62-item FFQ-6) and the possibility of identifying dietary patterns (DPs) in 13-21-year-old females. The study involved 97 females within three age groups: 13-15, 16-18, and 19-21 years, including 31, 38, and 28 subjects, respectively. The questionnaire was completed twice with a two-week interval (test and retest). For the total sample, using a principal component analysis (PCA), two similar PCA-driven DPs (DP1 and DP2) were identified separately from test data and retest data, considering two sets of input variables. 60-item-DP1 and 60-item-DP2 were identified after excluding two items-vegetables and fruits in general-due to including single items of various kinds of vegetables and fruits. After an aggregation of some items of the questionnaire, 25-item-DP1 and 25-item-DP2 were identified. The kappa statistic (test vs. retest) in the total sample averaged at 0.52 (0.32-0.72 for food items), while within age groups, it averaged at 0.41, 0.53, and 0.65, respectively. The percentage of subjects classified into the same food frequency category (test vs. retest) in the total sample averaged at 68% (51%-89% for food items), while within age groups, it averaged at 60%, 68%, and 77%, respectively. The Spearman correlations between dietary pattern scores (test vs. retest) in the total sample were: 0.84 (within age groups 0.83, 0.81, and 0.78, respectively) for 60-item-DP1, 0.68 (within age groups 0.24, 0.79, and 0.76, respectively) for 60-item-DP2, 0.76 (within age groups 0.56, 0.82, and 0.89, respectively) for 25-item-DP1, and 0.48 (within age groups 0.40, 0.57, and 0.53, respectively) for 25-item-DP2 (p < 0.05 for all). In conclusion, the test-retest reproducibility of the 62-item FFQ-6 was good or very good for most food items, with a tendency to be higher in older age groups of females under study. Due to the acceptable-to-good reproducibility of dietary pattern identification, the use of a 62-item FFQ-6 to describe the overall diet of young Polish females can be recommended.

Dietary patterns and cardiometabolic risk factors among adolescents: systematic review and meta-analysis

This study systematised and synthesised the results of observational studies that were aimed at supporting the association between dietary patterns and cardiometabolic risk (CMR) factors among adolescents. Relevant scientific articles were searched in PUBMED, EMBASE, SCIENCE DIRECT, LILACS, WEB OF SCIENCE and SCOPUS. Observational studies that included the measurement of any CMR factor in healthy adolescents and dietary patterns were included. The search strategy retained nineteen articles for qualitative analysis. Among retained articles, the effects of dietary pattern on the means of BMI (n 18), waist circumference (WC) (n 9), systolic blood pressure (n 7), diastolic blood pressure (n 6), blood glucose (n 5) and lipid profile (n 5) were examined. Systematised evidence showed that an unhealthy dietary pattern appears to be associated with poor mean values of CMR factors among adolescents. However, evidence of a protective effect of healthier dietary patterns in this group remains unclear. Considering the number of studies with available information, a meta-analysis of anthropometric measures showed that dietary patterns characterised by the highest intake of unhealthy foods resulted in a higher mean BMI (0·57 kg/m²; 95 % CI 0·51, 0·63) and WC (0·57 cm; 95 % CI 0·47, 0·67) compared with low intake of unhealthy foods. Controversially, patterns characterised by a low intake of healthy foods were associated with a lower mean BMI (−0·41 kg/m²; 95 % CI −0·46,−0·36) and WC (−0·43 cm; 95 % CI −0·52,−0·33). An unhealthy dietary pattern may influence markers of CMR among adolescents, but considering the small number and limitations of the studies included, further studies are warranted to strengthen the evidence of this relation.

Consumption of ultra-processed foods and body fat during childhood and adolescence: a systematic review

Objective

To review the available literature on the association between consumption of ultra-processed foods and body fat during childhood and adolescence.

Design

A systematic review was conducted in the PubMed, Web of Science and LILACS databases. Studies that evaluated the association between consumption of ultra-processed food (exposure) and body fat (outcome) during childhood and adolescence were eligible.

Subjects

Healthy children and adolescents.

Results

Twenty-six studies that evaluated groups of ultra-processed foods (such as snacks, fast foods, junk foods and convenience foods) or specific ultra-processed foods (soft drinks/sweetened beverages, sweets, chocolate and ready-to-eat cereals) were selected. Most of the studies (n15) had a cohort design. Consumption was generally evaluated by means of FFQ or food records; and body composition, by means of double indirect methods (bioelectrical impedance analysis and skinfolds). Most of the studies that evaluated consumption of groups of ultra-processed foods and soft drinks/sweetened beverages found positive associations with body fat.

Conclusions

Our review showed that most studies have found positive associations between consumption of ultra-processed food and body fat during childhood and adolescence. There is a need to use a standardized classification that considers the level of food processing to promote comparability between studies.

A systematic review of factors affecting energy intake of adolescent girls

BACKGROUND

Adolescence is considered a critical period marked by an increase in energy intake to meet the body's physiological needs especially during puberty. This study reviews existing literature and critically analyses factors associated with eating habits and energy intake of adolescent girls.

METHODS

A comprehensive search was conducted to identify at least 200 peer reviewed articles which dealt with the factors affecting energy intake (EI) and eating habits of adolescent girls. Studies were identified using a reference period between 1994 and 2016, based primarily on the PubMed/ CINL/ Science Direct/Google Scholar databases using keywords adolescent/ teenagers, factors/determinants and energy intake.

RESULTS

No studies investigated all factors affecting energy intake among adolescents. Some studies found mixed association among the determinants of EI in adolescent girls. However, a number of reviews confirm that many factors namely physical activity level, socio-economic status, diet, individual and social factors do contribute to either a higher or a lower EI of adolescents.

CONCLUSION

There is a dire need to consider factors associated with EI when designing nutritional intervention programs to prevent health problems in adulthood. The goal is not to change behavior of all but to increase the percentage of people adopting healthier lifestyle.

Associations between physical activity patterns and dietary patterns in a representative sample of Polish girls aged 13-21 years: a cross-sectional study (GEBaHealth Project)

BACKGROUND

Similar to other countries, trends of decreasing levels of physical activity (PA) and an increasing prevalence of unhealthy dietary patterns are observed among girls in Poland. Better understanding of potentially inter-related behaviours within this population can help to design tailored interventions. The purpose of this study was to determine associations between PA patterns and dietary patterns in a representative sample of Polish girls.

METHODS

Girls aged 13-21 years (n = 1107) were randomly selected for the study. PA was assessed using International Physical Activity Questionnaire - Long (IPAQ-L). Dietary data were collected with food frequency questionnaires. PA patterns and dietary patterns were drawn separately by Principal Component Analysis (PCA). Logistic regression was used to find the associations between PA patterns and dietary patterns.

RESULTS

Four major PA patterns ('School/work activity', 'Active recreation', 'Yard activity' and 'Walking and domestic activity') and four dietary patterns ('Traditional Polish', 'Fruit & vegetables', 'Fast food & sweets' and 'Dairy & fats') were identified. Level of PA was the highest in the upper tertile of 'School/work activity' pattern (mean 1372.2 MET-minutes/week, 95 % Confidence Intervals [CI]: 1285.9-1458.5). Girls in upper tertiles of 'Yard activity', 'Active recreation' and 'School/work activity' patterns had significantly higher chances of being in the upper tertile of the 'Fruit and vegetables' dietary pattern (odds ratio [OR] 2.17, 95 % CI: 1.50-3.14, p < 0.0001; OR 2.02, 95 % CI: 1.41-2.91; p < 0.001 and OR 1.76, 95 % CI: 1.24-2.51, p < 0.01 respectively; all adjusted for confounders) in comparison to bottom tertiles. Weak, but significant inverse associations were found between upper tertiles of 'Active recreation' and 'Yard activity' patterns and unhealthy dietary patterns.

CONCLUSIONS

We found associations between PA patterns and dietary patterns in the population of Polish girls. Girls with the highest adherence to the 'School/work activity' pattern had the highest levels of PA and presented pro-healthy dietary behaviours. School should be recognised as potentially efficient and important setting to maximise girls' PA potential. The after-school time is the area that should also be targeted to increase daily PA or to at least sustain the level of PA after completing education.

Analysis of Dietary Pattern Impact on Weight Status for Personalised Nutrition through On-Line Advice: The Food4Me Spanish Cohort

Obesity prevalence is increasing. The management of this condition requires a detailed analysis of the global risk factors in order to develop personalised advice. This study is aimed to identify current dietary patterns and habits in Spanish population interested in personalised nutrition and investigate associations with weight status. Self-reported dietary and anthropometrical data from the Spanish participants in the Food4Me study, were used in a multidimensional exploratory analysis to define specific dietary profiles. Two opposing factors were obtained according to food groups’ intake: Factor 1 characterised by a more frequent consumption of traditionally considered unhealthy foods; and Factor 2, where the consumption of “Mediterranean diet” foods was prevalent. Factor 1 showed a direct relationship with BMI (β = 0.226; r² = 0.259; p < 0.001), while the association with Factor 2 was inverse (β = −0.037; r² = 0.230; p = 0.348). A total of four categories were defined (Prudent, Healthy, Western, and Compensatory) through classification of the sample in higher or lower adherence to each factor and combining the possibilities. Western and Compensatory dietary patterns, which were characterized by high-density foods consumption, showed positive associations with overweight prevalence. Further analysis showed that prevention of overweight must focus on limiting the intake of known deleterious foods rather than exclusively enhance healthy products.

Impact of diet on cardiometabolic health in children and adolescents

The manifestation of cardiovascular risk factors, such as hypertension, diabetes, and particularly obesity begins in children and adolescents, with deleterious effects for cardiometabolic health at adulthood. Although the impact of diet on cardiovascular risk factors has been studied extensively in adults, showing that their cardiometabolic health is strongly lifestyle-dependent, less is known about this impact in children and adolescents. In particular, little is known about the relationship between their dietary patterns, especially when derived a posteriori, and cardiovascular risk. An adverse association of cardiovascular health and increased intake of sodium, saturated fat, meat, fast food and soft drinks has been reported in this population. In contrast, vitamin D, fiber, mono-and poly-unsaturated fatty acids, dairy, fruits and vegetables were positively linked to cardiovascular health.

The aim of this review was to summarize current epidemiological and experimental evidence on the impact of nutrients, foods, and dietary pattern on cardiometabolic health in children and adolescents. A comprehensive review of the literature available in English and related to diet and cardiometabolic health in this population was undertaken via the electronic databases PubMed, Cochrane Library, and Medline.

Cardiorespiratory fitness is positively associated with a healthy dietary pattern in New Zealand adolescents

OBJECTIVE

To examine the association between cardiorespiratory fitness and dietary patterns in adolescents.

DESIGN

Food choice was assessed using the validated New Zealand Adolescent FFQ. Principal components analysis was used to determine dietary patterns. Trained research assistants measured participants' height and body mass. Cardiorespiratory fitness was assessed in a subset of participants using the multistage 20 m shuttle run. The level and stage were recorded, and the corresponding VO2max was calculated. Differences in mean VO2max according to sex and BMI were assessed using t tests, while associations between cardiorespiratory fitness and dietary patterns were examined using linear regression analyses adjusted for age, sex, school attended, socio-economic deprivation and BMI.

SETTING

Secondary schools in Otago, New Zealand.

SUBJECTS

Students (n 279) aged 14-18 years who completed an online lifestyle survey during a class period.

RESULTS

Principal components analysis produced three dietary patterns: 'Treat Foods', 'Fruits and Vegetables' and 'Basic Foods'. The 279 participants who provided questionnaire data and completed cardiorespiratory fitness testing had a mean age of 15·7 (sd 0·9) years. Mean VO2max was 45·8 (sd 6·9) ml/kg per min. The 'Fruits and Vegetables' pattern was positively associated with VO2max in the total sample (β=0·04; 95%CI 0·02, 0·07), girls (β=0·06; 95% CI 0·03, 0·10) and boys (β=0·03; 95% CI 0·01, 0·05).

CONCLUSIONS

These results indicate that increase in cardiorespiratory fitness was associated with a healthier dietary pattern, suggesting both should be targeted as part of a global lifestyle approach. Longitudinal studies are needed to confirm this association in relation to health outcomes in New Zealand adolescents.

Controversies in fat perception

Nutritional fat is one of the most controversial topics in nutritional research, particularly against the background of obesity. Studies investigating fat taste perception have revealed several associations with sensory, genetic, and personal factors (e.g. BMI). However, neuronal activation patterns, which are known to be highly sensitive to different tastes as well as to BMI differences, have not yet been included in the scheme of fat taste perception. We will therefore provide a comprehensive survey of the sensory, genetic, and personal factors associated with fat taste perception and highlight the benefits of applying neuroimaging research. We will also give a critical overview of studies investigating sensory fat perception and the challenges resulting from multifaceted methodological approaches. In conclusion, we will discuss a multifactorial approach to fat perception to gain a better understanding of the underlying mechanisms that cause varying fat sensitivity which could be responsible for overeating. Such knowledge might be beneficial in new treatment strategies for obesity and overweight.

Dietary Patterns of Young Females and Their Association With Waist Circumference as a Health Index in Northwest of Iran, 2007

Background:

Despite the higher prevalence of overweight and obesity among young people in western countries, the 50th and 95th percentile ranks for waist circumference in the Iranian young Females are higher than those of the western ones.

Objectives:

Identifying major dietary patterns in Iranian young females, which associate with central obesity, can probably explain the difference between Iranian young females’ pattern and those of their western peers regarding obesity.

Patients and Methods:

In the current cross-sectional study, a total of 257 young females aged 11 - 15 years old from Talaat Intelligent Guidance School, Tabriz, Iran (2007) were selected for the study using non-probability simple sampling method. Then, usual dietary intakes of all subjects were evaluated by a food frequency questionnaire and anthropometric measurements such as weight, height, waist circumference, and Body Mass Index (BMI) using the standard protocols. Data were analyzed by inferential statistics (One-way ANOVA, Tukey test for Post-Hoc Analysis, Chi-square test, age-adjusted means, analysis of covariance with Bonferroni correction, correlation and partial correlation) by SPSS software.

Results:

In the current study, six major dietary patterns were extracted using factor analysis method. Before and after controlling the age, subjects in the upper tertile of the Iranian Central Obesity Making Dietary Pattern (rich in cruciferous vegetables, green leafy vegetables, soft drinks, tomatoes, other vegetables and vegetable oils) had larger waist circumference in comparison with the ones in the lower tertile (before controlling for age: 64.2 ± 9 vs. 61.6 ± 7 P = 0.03; after: 64.5 ± 0.8 vs. 61.5 ± 0.8, P = 0.009). However in lacto vegetarian dietary pattern (rich in legumes, potato, other vegetables, dough, high-fat dairy products and margarine), individuals in the upper tertile had significantly lower weight, waist circumference and body mass index (BMI) in comparison with the ones in the lower tertile (weight: 44.9 ± 9.3 vs. 51.4 ± 10.6, P < 0.01; WC: 59.9 ± 8 vs. 64 ± 7.9, P < 0.01; BMI: 18.6 ± 3.1 vs. 20.6 ± 3.5, P < 0.01).

Conclusions:

The current study findings suggest that the Iranian Central Obesity Making Dietary Pattern is directly associated with waist circumference (marker of central obesity), while lacto vegetarian dietary pattern is reversely associated with weight, waist circumference and BMI. Special obesity pattern in Iranian young females can be justified by Iranian Central Obesity Making Dietary Pattern”.

What factors are associated with frequent unhealthy snack-food consumption among Australian secondary-school students?

OBJECTIVE

To examine demographic and behavioural correlates of unhealthy snack-food consumption among Australian secondary-school students and the association between their perceptions of availability, convenience and intake with consumption.

DESIGN

Cross-sectional survey of students' eating, physical activity and sedentary behaviours using validated instruments administered via an online questionnaire.

SETTING

Australian secondary schools across all states/territories.

SUBJECTS

Secondary-school students aged 12-17 years participating in the 2009-10 National Secondary Students' Diet and Activity (NaSSDA) survey (n 12 188).

RESULTS

Approximately one in five students (21 %) reported consuming unhealthy snack foods ≥14 times/week ('frequent snackers'). After adjusting for all covariates, older students and those with a BMI of ≥25 kg/m² were less likely to be frequent snackers, while students who reported high fast-food and high sugar-sweetened beverage consumption and those who watched television for >2 h/d were more likely to snack frequently. Furthermore, after adjusting for all covariates and demographic factors, students who agreed that snack foods are usually available at home, convenient to buy and that they eat too many snack foods were more likely to be snacking frequently. Conversely, students who agreed that fruit is a convenient snack were less likely to be frequent snackers.

CONCLUSIONS

Frequent unhealthy snack-food consumption appears to cluster with other poor health behaviours. Perceptions of availability and convenience are factors most readily amenable to change, and findings suggest interventions should focus on decreasing the availability of unhealthy snack foods in the home and promoting healthier options such as fruit as convenient snacks.

Dietary patterns of Brazilian adolescents: results of the Brazilian National School-Based Health Survey (PeNSE)

The objectives of this study were to identify dietary patterns in Brazilian adolescents, describe their distributions in Brazil's State capitals and Federal District, and analyze the correlations with the Municipal Human Development Index (HDI-M). The study analyzed a sample of 60,954 ninth-graders from public and private schools who participated in the National School-Based Health Survey (PeNSE) in 2009. Cluster analysis was used to characterize dietary patterns. Three patterns were identified: healthy (27.7%), unhealthy (34.6%), and mixed (37.7%). Adolescents in the country's Southeast, South, and Central West regions showed a higher proportion of the healthy eating pattern. HDI-M showed a positive correlation with the healthy pattern and a negative correlation with the mixed pattern. The identification of different dietary patterns within and between regions and according to HDI-M highlights the need for better knowledge of each local context in terms of both the magnitude of events and the examination of determinants within these different realities.

Is the food environment surrounding schools associated with the diet quality of adolescents in Otago, New Zealand?

Using a sample of adolescents from schools in Otago, New Zealand, associations between food outlets around schools and dietary quality were investigated. Food outlet environment data were derived using GIS data. Multivariate regression analysis results showed that outlet density, in an 800m buffer around schools, of cafes and restaurants, supermarkets and takeaways was associated with higher Diet Quality Index scores in boys, and distance to nearest outlet for convenience stores, cafes and restaurants and supermarkets with lower scores for girls. Effect sizes were small, suggesting that the food environment around schools plays a minor role in adolescent diet quality.