Dietary Intake In Adolescents Research Articles

Dietary intake in adolescents with asthma – potential for improvement

Associations between an unhealthy diet and overweight and the presence of asthma are reported. The aims of this study were to assess whether the intake of nutrients and food items in adolescents with asthma differs from that of healthy adolescents, whether the intake was in accordance with the Nordic Nutrition Recommendations (NNR) or whether possible relationships were confounded by body composition. A four-day-validated 18-page pre-coded food diary was completed by 169 13- to 14-year-old adolescents, 93 with asthma and 76 healthy control subjects, in addition to clinical assessment, anthropometric measurements, lung function and skin prick tests. Neither intake of added sugar, snacks nor saturated fat was associated with asthma. All groups had an intake of saturated fat and added sugars exceeding the NNR, while the intake of fruits and vegetables, fibre and vitamin D was lower than recommended. The intake of folate, calcium, magnesium and iron was lower than recommended for girls with asthma and healthy girls. The intake of vitamin C was satisfactory for all groups. Body composition did not influence eating habits, and the prevalence of overweight was similar in the two groups. The dietary intake among Norwegian adolescents in general had a potential for improvement. As girls have a lower energy intake than boys, they have a larger demand of quality of the diet. Additional dietary research in adolescents with asthma is recommended.

Neighbourhood food environment and dietary intakes in adolescents: Sex and perceived family affluence as moderators

To examine the effects of perceived availability of fast-food shops, restaurants, and convenience stores on adolescent dietary intakes. Survey data from 34 369 students in 42 Hong Kong secondary schools were collected in 2006-7. Respondents reported the availability of fast-food shops, restaurants and convenience stores in the neighbourhood, and their intakes of fruit, vegetables, high-fat foods and junk food/soft drinks. For intakes of high-fat foods and junk food/ soft drinks, ≤ once a week was defined as low consumption and the rest moderate/high consumption. At least three servings of vegetables and two servings of fruit daily were defined as sufficient consumption. Logistic regression yielded adjusted odds ratios (OR) for each dietary intake in relation to the reported food shops. Potential effect modifications by socio-demographic factors were also examined. Perceived availability of fast-food shops and convenience stores were positively associated with moderate/high consumptions of high-fat foods (OR(fast) =1.10 and OR(con) =1.15) and junk food/soft drinks (OR(fast)=1.10 and OR(con) =1.10). Significant negative associations of the perceived availability of restaurants with intakes of vegetables and fruit were observed (OR(veg) =0.87 and OR(fruit) =0.83). The positive relationship between reporting fast-food shops with intake of junk food/soft drinks were observed only in boys and those with low perceived family affluence. The negative association of reporting restaurants with fruit consumption was found in those with low and middle perceived family affluence only. Perceived availability of neighbourhood fast-food shops, restaurants, and convenience stores may have a negative impact on adolescent dietary intakes particularly for those from poorer families.

Neighbourhood food environments: are they associated with adolescent dietary intake, food purchases and weight status?

To examine neighbourhood food environments, adolescent nutrition and weight status. Cross-sectional, observational study. Minneapolis/St. Paul metropolitan region, Minnesota, USA. A total of 349 adolescents were recruited to the study. Participants completed 24 h dietary recalls and had their weight and height measured. They also reported demographic information and other diet-related behaviours. Geographic Information Systems were used to examine the availability and proximity of food outlets, particularly those captured within the 800, 1600 and/or 3000 m network buffers around participants' homes and schools. Adjusting for gender, age and socio-economic status, adolescents' sugar-sweetened beverage intake was associated with residential proximity to restaurants (including fast food), convenience stores, grocery stores and other retail facilities within the 800 and/or 1600 m residential buffers (P ≤ 0·01). BMI Z-score and percentage body fat were positively associated with the presence of a convenience store within a 1600 m buffer. Other individual-level factors, such as energy, fruit and vegetable intake, as well as convenience store and fast food purchasing, were not significantly associated with features of the residential neighbourhood food environment in adjusted models. In addition, school neighbourhood environments yielded few associations with adolescent outcomes. Many factors are likely to have an important role in influencing adolescent dietary intake and weight status. Interventions aimed at increasing neighbourhood access to healthy foods, as well as other approaches, are needed.

Use of the mobile telephone Food Record (mpFR) does not mitigate reduced dietary intake in adolescents

The mobile phone Food Record (mpFR) is a novel diet assessment tool (Six, 2010; Zhu 2009). Zepeda (2008) suggested that use of image‐based food records leads to reduced food intake. However, no quantitative analysis comparing self‐reported energy to expected energy intake (EEI) was reported. Our objective was to investigate the influence of mpFR use on EEI for meals and 24‐hr dietary intake. Distribution of energy intake (breakfast 16%, lunch 27%, dinner 33%, snacks 24%) was derived from results among 8th graders (Dwyer, 2001) and used to determine EEI as a percent of estimated energy requirement (EER). In a controlled setting, 26 boys and 51 girls aged 11–18 y used the mpFR to record meals eaten to satiation. Adolescents ate breakfast (n=70), lunch (n=78), and dinner and snacks (n=15). There was no significant difference between the EER and known energy consumed over 24‐hr (n=15, p = 0.352). Boys consumed significantly less energy from snacks than expected (mean difference 324 kcal, SE 111, p = 0.014). Girls consumed significantly more energy at dinner than expected (mean difference 196 kcal, SE 43, p = 0.044). Those with a BMI for age in the 85–95th percentile ate significantly less energy at lunch than expected (p = 0.047, mean difference 88 kcal). These results suggest that mpFR use does not mitigate behavior change in adolescents. The mpFR holds promise to accurately assess daily energy intake in adolescents.NCI, NIDDK

Is there a relationship between type of insulin regimen and dietary intake in adolescents with type 1 diabetes?

ABSTRACT OBJECTIVE: The literature indicates that adolescents with type 1 diabetes consume a diet high in fat, saturated fat and cholesterol, and low in fruit, vegetables and fibre. Information describing the relationship between insulin regimen and dietary intake is scarce. This study aimed to investigate and compare the impact of 3 insulin therapies— 3 times daily insulin (tid), multiple daily injections (MDI) and continuous subcutaneous insulin infusion (CSII)—on dietary intake of teens with type 1 diabetes. METHOD: Ninety-seven subjects aged 14 to 18 years were recruited during outpatient diabetes clinics at SickKids Hospital. Group distribution was as follows: tid (n=34), MDI (n=29) and CSII (n=34). Dietary intake information was collected using the validated Youth/Adolescent Food Frequency Questionnaire and analyzed for energy, carbohydrate, sucrose, fibre, protein, total fat and saturated fat. RESULTS: Using analysis of variance, no significant differences were found in any of the nutrients studied. Univariate and multiregression analyses also failed to reveal significant differences. All groups fell within the acceptable distribution ranges for all macronutrients, above the recommendation for saturated fat according to the 2008 Canadian Diabetes Association clinical practice guidelines and below the adequate intake for fibre. CONCLUSION: These data indicate that the choice of insulin regimen is not a major factor in predicting dietary intake.

The development of tools to measure the food environment of adolescents

It is hypothesised that the food environment influences eating behaviour and contributes to excessive intakes, which contribute to the aetiology of obesity. However, there has been little research on the characteristics of individual food environments and the research field is constrained by the lack of reliable tools for measuring individual food environments. This research aimed to develop methods and tools to characterise and quantify individual food environments and to measure the impact of the food environment on dietary intakes of adolescents.

Breakfast Consumption in Adolescence and Young Adulthood: Parental Presence, Community Context, and Obesity

Background Breakfast consumption is often examined when researching adolescent dietary intakes and overall health. However, fewer studies have examined the relationship between breakfast and obesity, particularly over time and in relation to weight outcomes in young adulthood. In addition, little is known about contextual factors influencing the likelihood of adolescents consuming breakfast on a regular basis. Objective The present study assessed individuals' breakfast consumption patterns and obesity status during adolescence and young adulthood. Analyses included the context in which breakfast consumption took place, specifically community and family factors. Design Participants' breakfast consumption patterns and obesity status were assessed at two developmental time points—adolescence (Wave 2) and young adulthood (Wave 3). Community disadvantage, family poverty, race, sex, and a parent's morning presence in the home, were examined for association with breakfast consumption. Subjects/setting Data used in this study (n=7,788) were derived from the National Longitudinal Study of Adolescent Health, a nationally representative study of adolescents. Data were collected as follows: Wave 1 (September 1994 to April 1995), Wave 2 (April 1996 to August 1996), and Wave 3 (August 2001 to April 2002). The final sample ranged in age from 12 to 19 years during Wave 2 and 18 to 26 years during Wave 3. Statistical analyses Multilevel random intercept regression models were used to examine the association between community, parental, and individual predictors on adolescent and young adult weight outcomes. Results Adolescent regular breakfast consumption significantly predicted young adult regular breakfast consumption ( P<0.001) and an important factor associated with adolescents eating breakfast was having at least one parent home in the morning. Regular consumption during both developmental periods provided considerable protection from obesity during adolescence and young adulthood (ie, chronic obesity). Residing in disadvantaged communities decreased the odds adolescents would eat breakfast during adolescence and increased their chances for chronic obesity. African Americans were less likely to eat breakfast during adolescence and young adulthood, while also being at greater risk for chronic obesity compared to whites. Conclusions Results indicate that low-income youth in disadvantaged communities, especially African Americans, should be specifically targeted for nutrition interventions related to breakfast consumption. In addition, parental promotion of breakfast at home and/or engagement with schools to develop or strengthen school-based breakfast programs may be a powerful addition to nutrition interventions for youth at risk for lifelong struggles with obesity and other nutrition-related problems.

Major Patterns of Dietary Intake in Adolescents and Their Stability over Time

A diet-patterns approach has often been used to describe eating patterns in adults but has rarely been used in adolescents. We used principal components factor analysis to: 1) describe the dietary patterns of a cohort of ethnically diverse youth during early and middle adolescence; 2) examine if the patterns persisted 5 y later; and 3) study secular trends. Project EAT-I (Time 1) collected data on 4746 middle school (younger cohort) and high school (older cohort) students in 31 Minnesota schools in 1998-1999. Project EAT-II (Time 2) resurveyed 53% (n = 2516) of the original cohort in 2003-2004. Dietary intake was assessed at Time 1 and 2 using the Youth/Adolescent FFQ. We identified dietary patterns separately by cohort (older/younger) and gender (boys/girls). At Time 1, we identified 4 patterns in early and middle adolescents that were relatively consistent between boys and girls that we labeled vegetable, fruit, sweet/salty snack food, and starchy food. Longitudinal analyses indicated that patterns were relatively stable over 5 y, with the exception of a new fast food pattern. Examination of age-matched secular trends in middle adolescents (older cohort at Time 1, younger cohort at Time 2) showed similar patterns, with the exception of the fast food pattern that emerged at Time 2 among middle adolescent boys. We identified dietary patterns in this adolescent population that differed from those usually found in adults. Patterns were similar across gender and age cohorts and were relatively similar over time, with the exception a new fast food pattern.

Within- and between-person variations as determinant factors to calculate the number of observations to estimate usual dietary intake of adolescents

This cross-sectional study describes the variation in the dietary intake of energy and macronutrients based on estimated coefficients of within- and between-person variation and intends to calculate the number of days required to evaluate the dietary intake of adolescents in Piracicaba, Brazil. The sample was made up by ninety-two adolescents aged between eleven and sixteen years. Interviews were performed to assess demographic, anthropometric and dietary variables, which were evaluated by the answers obtained through two 24-hour recalls. Descriptive analyses were performed and variances and Coefficients of variation within- and between-person were obtained by results of one-way ANOVA. The mean energy intake observed was 2,326.2 kilocalories; mean macronutrient intake came to 89.0 grams of fatty acids, 305.3 grams of carbohydrates and 82.2 grams of proteins. Coefficients of within-person variation ranged from 36% to 45%, while between-person coefficients varied from 26% to 31%. Variance ratios ranged from 1.35 (carbohydrate) to 2.62 (protein). The lowest number of observations required to correctly evaluate the usual diet calculated (r = 0.90) was six days, for carbohydrates while the highest was eleven, for proteins. Coefficients of variation were similar to those observed in international studies. We conclude that, in this study, two observations were sufficient to obtain reasonable correlations. However, six evaluations are necessary for these adolescents in order to obtain excellent correlations.

Estado nutricional e consumo alimentar de adolescentes da rede pública de ensino da cidade de São Mateus do Sul, Paraná, Brasil

OBJETIVOS: caracterizar o estado nutricional e consumo alimentar de adolescentes da rede pública de ensino de São Mateus do Sul, Paraná, Brasil. MÉTODOS: o Índice de Massa Corporal foi calculado e classificado pela proposta da Organização Mundial da Saúde. O consumo alimentar foi obtido pelo Questionário de Freqüência de Consumo Alimentar. Foi utilizada análise descritiva, de freqüência e teste t de Student com p&lt;0,05. RESULTADOS: a maioria dos indivíduos apresentou estado nutricional normal (84% eutróficos, 12% sobrepeso/obesidade e 4% baixo peso). A dieta caracterizou-se por consumo energético adequado, com distribuição de macronutrientes de acordo com as recomendações, sendo maior nos meninos do que nas meninas. Noventa por cento dos adolescentes consumiam ácidos graxos em excesso. Verificou-se consumo adequado de vitamina C (287 mg meninos e 328 mg meninas) e ferro (27 e 21 mg, respectivamente). O consumo de ferro diferiu estatisticamente entre os sexos (t=3,765; p&lt;0,001). CONCLUSÕES: as anormalidades encontradas na alimentação evidenciam a necessidade de conhecer e avaliar o tipo de alimentação oferecida aos alunos, a fim de elaborar estratégias de intervenção dentro e fora das escolas, além de auxiliar a prevenção de problemas de saúde relacionados à alimentação.

Adolescent home food environments and socioeconomic position.

Many adolescents have diets that are less than optimal, particularly adolescents of low socioeconomic position (SEP). The determinants of SEP differences in adolescent dietary intake are poorly understood. This study examined the home food environments of adolescents and specifically investigated whether low SEP adolescents have less supportive home meal environments, fewer eating rules and poorer home availability of fruit and vegetables than adolescents of high SEP. A cross-sectional, self-reported survey was administered to 3,264 adolescents in years 7 and 9, from 37 secondary schools in Victoria, Australia. Adolescent perceptions of the home meal environment, eating rules and home food availability were described and compared across SEP, which was measured using maternal education. Maternal education was linked to various aspects of the home meal environment, as well as home food availability, but not to eating rules. Low SEP adolescents were more likely to report that they were always allowed to watch television during meal times, and that unhealthy foods were always or usually available at home. In contrast, high SEP adolescents were more likely to report that vegetables were always served at dinner, that the evening meal was never an unpleasant time and always or usually a time for family connectedness, and that fruit was always or usually available at home. This study highlights aspects of the home food environment that might explain SEP variation in adolescent diets. Feasible ways of increasing home availability of healthy foods, and encouraging home meal environments to be supportive of healthy eating should be explored, particularly in households of low SEP adolescents.

P36: Relationships Between Adolescent Vegetarianism, Dietary Intake, Weight, and Weight Control Behaviors

P36: Relationships Between Adolescent Vegetarianism, Dietary Intake, Weight, and Weight Control Behaviors

Dietary Intakes of Adolescents Living in Edirne, Turkey

Objective: To assess the dietary intakes of the adolescents in the area of Edirne, Turkey.Design: Cross-sectional, prospective, epidemiological study.Settings and Subjects: Our study group consists of 1944 adolescents aged between 12 to 17 years; 940 females and 1004 males.Interventions: Three-day self-reported food records were collected from the subjects and evaluated by a nutrient database program. Reported nutrient intake data were analyzed for gender differences. Minitab statistical program was used to compare nutritional data of subjects.Results: Energy, calcium, magnesium, folic acid, vitamins A, E, thiamine, and fiber intakes of whole adolescents, and also iron intakes of female adolescents were most likely to be inadequate compared with the recommendations. Iron, calcium, folic acid, thiamine, and fiber intakes were below two thirds of RDA/DRI in a large proportion of the adolescents. The intakes of protein, riboflavin, vitamin C, phosphorus and zinc were found to be adequate in a large percentage of the subjects. Forty eight percent of females and 60.1 % of males were below 2/3 of the RDA for energy.Conclusion: Pediatricians and dietitians should train the adolescents living in our region and our country on practical strategies for making healthy food choices rich in nutrient content relative to energy value to ensure intakes that approach the recommendations.

A Review of Family Meal InfluenceOn Adolescents’ Dietary Intake

Recent concerns about adolescent nutrition and unhealthy weights have prompted an examination of the myriad influences on dietary intake during adolescence. Included here are a summary of the literature on family influence on dietary intake, specifically during adolescence and within the family context, a summary of family meal patterns, and a systematic review of the known influences of family meals on dietary intake. Because of the complexity of families in today's society, models were developed to depict the broad context of familial influences on adolescent nutritional behaviours and attitudes and to describe what is known and not known about family meal influences on adolescent dietary intake and quality. A systematic review of the literature revealed seven articles specifically related to adolescents, family meals, and dietary intake, which were analyzed for strength of evidence and plausibility. In spite of data collection methods relying on self-report, results suggested that family meals were associated with improved dietary intakes. Families in today's societies are complex. Nevertheless, parents have the potential to influence positively, through family meals, what food is provided, where it is provided (e.g., home, restaurant), and within what type of atmosphere it is provided.

Nutrition Education for Adolescents: Perceiving is Real

Nearly half of this JNEB issue (Table) is devoted to adolescent nutrition concerns: adequate calcium intake, cooking skills, mealtime television viewing, and family influence on intake. Vue and Reicks 2 Vue H. Reicks M. Individual and environmental influences on intake of calcium-rich food and beverages by young Hmong adolescent girls. J Nutr Educ Behav. 2007; 39: 264-272 Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar studied 102 Hmong girls 10 to 13 years old and 20 Hmong parents to affirm the influential role of parents on adolescent calcium intake. Feldman, Eisenberg, Neumark-Sztainer, et al 1 Feldman S. Eisenberg M. Neumark-Sztainer D. Story M. Associations between watching TV during family meals and dietary intake among adolescents. J Nutr Educ Behav. 2007; 39: 257-263 Abstract Full Text Full Text PDF PubMed Scopus (141) Google Scholar reported a lower diet quality among adolescents eating meals while viewing television compared to those who turned the television off, but eating family meals, with or without the television, proved the stronger indicator of diet quality. Adolescents attending an 8-day summer culinary camp (with 8 4-hour sessions conducted over a 2 week period) described by Beets, Swanger, Wilcox, et al 7 Beets M.W. Swanger K. Wilcox D.B. Cardinal B.J. Using hands-on demonstrations to promote cooking behaviors with young adolescents: The culinary camp summer cooking program. J Nutr Educ Behav. 2007; 39: 288-289 Abstract Full Text Full Text PDF PubMed Scopus (31) Google Scholar noted no change in frequency of home cooking, but identified knowledge gains and perceived improved cooking ability. Boutelle, Birkeland, Hannan, et al 8 Boutelle K.N. Birkeland R.W. Hannan P.J. Story M. Neumark-Sztainer D. Associations between maternal concern for healthful eating and maternal eating behaviors, home food availability, and adolescent eating behaviors. J Nutr Educ Behav. 2007; 39: 248-256 Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar demonstrated the keen importance of adolescent perception on behavior by comparing maternal concern for healthful eating, maternal dietary intake, adolescent dietary intake, adolescent concern for healthful eating and adolescent perception of maternal concern for healthful eating. Adolescent dietary intake was most influenced by their perception of their mother’s concern for healthful eating, serving “… as a reminder that youth perceptions need to be assessed when evaluating interventions for teens.” 8 Boutelle K.N. Birkeland R.W. Hannan P.J. Story M. Neumark-Sztainer D. Associations between maternal concern for healthful eating and maternal eating behaviors, home food availability, and adolescent eating behaviors. J Nutr Educ Behav. 2007; 39: 248-256 Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar This finding leads to new questions. Were perceptions of what constituted home cooking responsible for the lack of change in home cooking behavior in the culinary camp 7 Beets M.W. Swanger K. Wilcox D.B. Cardinal B.J. Using hands-on demonstrations to promote cooking behaviors with young adolescents: The culinary camp summer cooking program. J Nutr Educ Behav. 2007; 39: 288-289 Abstract Full Text Full Text PDF PubMed Scopus (31) Google Scholar attendees? What role did Hmong adolescent 2 Vue H. Reicks M. Individual and environmental influences on intake of calcium-rich food and beverages by young Hmong adolescent girls. J Nutr Educ Behav. 2007; 39: 264-272 Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar perception of parental concern about calcium intake play in girls’ calcium intake? Was perception of what constituted a meal a factor in comparing dietary quality, family meals, and television viewing? 1 Feldman S. Eisenberg M. Neumark-Sztainer D. Story M. Associations between watching TV during family meals and dietary intake among adolescents. J Nutr Educ Behav. 2007; 39: 257-263 Abstract Full Text Full Text PDF PubMed Scopus (141) Google Scholar Development of eating competence in adults, examined in the supplement to this JNEB issue, requires that nutrition educators ask what nutrition program participants hear them saying, ie, what they perceive. 9 Satter E. Eating competence: Nutrition education with the Satter eating competence model. J Nutr Educ Behav. 2007; 39: S189-S194 Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar Outcomes from Boutelle, Birkeland, Hannan, et al 8 Boutelle K.N. Birkeland R.W. Hannan P.J. Story M. Neumark-Sztainer D. Associations between maternal concern for healthful eating and maternal eating behaviors, home food availability, and adolescent eating behaviors. J Nutr Educ Behav. 2007; 39: 248-256 Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar emphasize the need to start that practice with much younger learners.

Associations between Maternal Concern for Healthful Eating and Maternal Eating Behaviors, Home Food Availability, and Adolescent Eating Behaviors

Objective Evaluate the relationship between maternal concern for healthful eating and maternal and adolescent dietary intake, eating behavior, and home food environment. Design Mothers of a subsample of adolescents who participated in a school-based survey (Project Eating Among Teens [EAT]) completed telephone interviews. Participants Seven hundred fourteen mother–adolescent pairs. Variables Measured Mothers responded to a question regarding how much they are personally concerned with eating healthfully, and adolescents responded to a question regarding perceptions of their mothers’ concern about eating healthfully. Dependent variables included adolescent and parent food intake and home food environment. Analysis Multinomial cumulative logistic regression models, adjusted for maternal race/ethnicity, socioeconomic status (SES), and adolescent grade level. Results A positive association was found between maternal concern for healthful eating and maternal fruit and vegetable intake, maternal breakfast and lunch consumption, and serving fruits and vegetables in the home. Maternal concern for healthful eating (as reported by mothers) was not associated with adolescent behavior. Adolescent perception of maternal concern for healthful eating was positively associated with adolescent fruit and vegetable intake. Conclusions and Implications Mother’s concern for healthful eating is associated with maternal eating behavior and the home food environment. Adolescent perceptions of maternal attitudes are a stronger predictor than actual maternal attitudes of adolescent behavior. Parents should be encouraged to share their beliefs regarding the importance of healthful eating with their adolescents.

Differences Between Parents’ and Adolescents’ Perceptions of Family Food Rules and Availability

Objective To test the hypotheses that adolescents have different perceptions of family-environmental factors than do their parents, and that dietary intake of adolescents is more highly associated with the adolescent’s own perceptions than those of their parents. Design Data from self-administered questionnaires were used. Participants Five-hundred two students aged 12 to 14 years, and one of each student’s parents. Main Outcome Measures Two types of family-environmental factors (ie, family food rules and home availability and accessibility of food) for 3 self-reported dietary behaviors (ie, fruit, snack, and breakfast intake). Analysis Unpaired t tests, chi-square tests, percentage (gross) disagreement, standardized regression coefficients, and linear regression analyses. Results For most rules and most perceptions of availability and accessibility, considerable disagreement was found between parents and students. Self-reported intake of fruit and snacks was more highly associated with student measures, but breakfast intake was more highly associated with parent measures of rules and availability. Implications for Research and Practice The findings might explain mixed results on the associations between family-environmental factors and children’s dietary intake that were found in earlier studies. Researchers need to be aware that in studies into family-environmental determinants of dietary habits using self-reports, the results are possibly influenced by whether the data were reported by parents or by children.

Adolescent dietary phytoestrogen intake and breast cancer risk (Canada)

It has been suggested that dietary phytoestrogen intake during adolescence may reduce the risk of developing breast cancer. This population-based case-control study evaluated the association between adolescent dietary phytoestrogen intake and adult breast cancer risk among women in Ontario, Canada. Pathology-confirmed, population-based breast cancer cases, aged 25-74 years, diagnosed between June 2002 and April 2003, were identified using the Ontario Cancer Registry. Population-based controls were recruited, and matched to cases within 5-year age groups. Adolescent phytoestrogen intake was obtained using a brief food frequency questionnaire (n = 3,024 cases, n = 3,420 controls). Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Higher phytoestrogen intake (both isoflavones and lignans) during adolescence was associated with a reduced breast cancer risk, and a monotonic trend was observed from the lowest to the highest quartile (OR [Q2] = 0.91, 95% CI 0.79-1.04, OR[Q3] = 0.86, 95% CI 0.75-0.98, and OR[Q4] = 0.71, 95% CI 0.62-0.82, p-trend < 0.001). Adolescent dietary phytoestrogen intake may be associated with a decreased risk of adult breast cancer. If verified, this finding has important implications with regard to breast cancer prevention since diet is a potentially modifiable factor.

School Region Socio-economic Status and Geographic Locale is Associated with Food Behaviour of Ontario and Alberta Adolescents

In an attempt to elucidate broader determinants of adolescent dietary intake and habits, food intakes and selected food behaviours of grades 9 and 10 students from Ontario and Alberta were examined according to school region socio-economic status and urban/rural locale. Using a stratified random sample framework, 53 high schools from 28 school boards were recruited (45 public and 8 private; 33 urban and 20 rural). Median family income for Canada Post's forward sortation area of the school was used to define school region SES. Public and private schools were compared as a proxy measure of SES. A web-based survey of food intake and behaviours, including a 24-hour diet recall and food frequency questionnaire, was completed by 2,621 students in grades 9 and 10. Comparison of intakes and behaviours by school designation as urban/rural, public/private or regional SES (generalized linear model procedure) controlled for student gender and grade distribution and number of participants within schools. School region SES ranged from dollars 40,959 to dollars 85,922/year. Vegetable and fruit consumption (p < 0.001), fibre intake (p < 0.001) and frequency of breakfast consumption (p < 0.01) increased with increasing income, while added sugar intake decreased (p < 0.01). Private versus public school students had lower intakes of sweetened drinks (p < 0.01) and higher intakes of fibre (p=0.02). Rural students reported higher mean intakes of calcium (1106 vs. 995 mg/day, respectively, p = 0.03) and milk products (2.7 vs. 2.3 servings/day, p < 0.01) than urban students. Selected food behaviours of youth from Ontario and Alberta improve with increasing school SES and vary with rural/urban school locale. Identifying regional demographics may be useful in tailoring healthy eating programs to the specific school.

Validation of a semi-quantitative adolescent food frequency questionnaire applied at a public school in São Paulo, Brazil.

To develop a food frequency questionnaire for adolescents (AFFQ) and demonstrate its relative validity. The final version of the AFFQ was composed of 76 food items previously identified according to their contribution in nutrients and overall importance within the eating habits of this population group. The validation study, which was undertaken during a 6 month period (June to November 1999), was administered to a sample of 79 who answered at least three 24 h dietary recalls (R24 h) applied at intervals of 45 days and one AFFQ at the end of the study. Applying the paired t-test and calculating Pearson correlation coefficients on nutrient data, differences in the mean of nutrients were obtained. Correlation coefficients between the mean energy-adjusted nutrients computed by the two methods were calculated, and correction was made for within-person variability. Agreement was evaluated by distribution of the adolescents according to quartiles of consumption. LOCUS: A public school within the metropolitan region of São Paulo city. A high variability in the dietary intake of adolescents was observed, with high rates of variability for cholesterol, retinal and vitamin C. The Pearson correlation coefficients, after being adjusted and corrected for variability, ranged from 0.10 to 0.72 among females and from 0.16 and 0.91 among males. The mean correlation coefficient for the entire group was 0.52. These results indicate that the AFFQ provides a potentially reliable scale for categorizing individuals by level of past intake of most nutrients, excluding retinol and iron.