Heightened reward associated with palatable food, a construct referred to as hedonic reward, can promote excessive energy intake among adults. However, no known studies have examined the influence of hedonic reward on adolescents' eating behavior and weight status. The present study examined whether there was an association between hedonic hunger and weight status in overweight/obese adolescents and whether dietary behavior (caloric consumption) mediated this association. Baseline measures of body mass index, hedonic food reward, and dietary intake were collected from one hundred overweight and obese adolescents. Data were analyzed using mixture modeling. Mediation at varying levels of hedonic hunger was explored and three heterogeneous sub-classes were identified. Results indicated that for 65% participants there was a positive association between hedonic hunger and zBMI such that one unit of increase in hedonic hunger was associated with a 0.35 unit increase in zBMI. However, no conclusive evidence of caloric intake mediating the association between hedonic hunger and weight-status was found. Overall, our results suggest that exaggerated hedonic responses are associated with higher body mass in adolescents. These results provide a compelling argument that hedonic hunger can potentially override the homeostatic need for energy and may be associated with weight-gain.

Studies have supported the benefits of positive dietary behaviors in preventing or reducing morbidity and extending longevity, as well as the psychosocial function of dietary practices for quality of life. Research is needed though on the dietary behaviors of elders in general and older women in particular, for whom gender affects lifelong dietary patterns. Health behavior theory has typically focused on psychological factors, to the neglect of sociocultural processes. This investigation utilized a life course perspective, enhanced by social interactionist elements, to address aspects of development and change in behavior neglected by health behavior theories, such as temporal dimensions and social contexts. Using primarily an ethnographic approach centered on in-depth narrative interviews of 18 older women residing in a retirement community, this study explored how social milieu influences the development and progression of dietary behavior throughout life, the potential of life course transitions to modify dietary behavior, and how the retirement community environment shapes current dietary behavior. The interviews probed current dietary experiences and practices, as well as constructed histories of dietary behavior. Through the use of coding techniques and thematic analysis, themes and concepts that emerged from the data were organized for further analysis. Four levels of influence on dietary behavior were identified: 1) person factors, including psychological and physiological processes; 2) interpersonal relationships and social interaction; 3) social roles and statuses; and 4) contexts, particularly environmental, community policy and political economic contexts. Analysis additionally revealed four major food-related themes in the lives of the women: dietary morality, dietary wellness, dietary sociability and dietary duty. Interpretation of the findings, in terms of lifelong social experiences, the impact of relationships, roles and transitions, and structural characteristics of the retirement community that constrain or facilitate dietary practices, contributed to the development of a theoretical model. The research findings and model of life course influences on the nature of dietary behaviors of older women provide a more holistic understanding of dietary practices of older women and have implications for future research and practice, particularly as related to quality of life issues.

Worldwide, there is a growing burden of non-communicable diseases (NCDs). The rise has coincided with the increase in prevalence of overweight and obesity. The ANGELO framework recognises the role of environmental influences in weight gain. In Africa, various environmental influences have led to shifts from a traditional dietary patterns and more physical lifestyles to a “Western” dietary pattern and low physical activity. The life course perspective posits that excessive body weight can persist from adolescence to adulthood, and increase the risk of NCDs. Among adolescents the school environment is a crucial setting for the development of and, or engagement in unhealthy dietary and physical activity behaviour. The aim of this thesis was to investigate in the school environment, the consumption of energy dense foods (EDFs) and energy dense beverages (EDBs) as are typical of a “Western” dietary pattern, and physical inactivity among a sub-group of adolescents in Nairobi, Kenya. Also, the sources of food in the school environment, and the attitudes to the importance of diet and physical activity for health were assessed. A cross-sectional survey was conducted among 402 adolescents aged 13-19 years. The adolescents were recruited from schools that cater to students from households likely to be of at least middle-income socio-economic status. Results indicate that the majority of adolescents reported the consumption of an EDB (82.3%) and EDF (88.3%) at least once during the school day. Nearly half of the adolescents consumed a meal sourced from a school lunch program (45.9%). In terms of weekly consumption, the items that were reported as frequently consumed by the highest proportion of adolescents were sugar sweetened beverages (46.5%), and pastries such as biscuits and cakes (38.8%,). Both the occasional and frequent participation in team sports (50.5%) more common than individual (27.4%) and gym based workouts (26.4%). The majority (88.1%) of adolescents acknowledged the importance of diet and exercise for health. Rigorous measurement of diet and physical activity behaviour and knowledge and attitude of health behaviour in this thesis was limited. Also, the sample used was not representative of adolescents in Kenya. The findings of this thesis are preliminary and further research is recommended using a representative sample and validated data collection methods. Research of this nature can be used in the adoption of school food and exercise policies to promote healthy behaviours and, on a national level, the development of dietary guidelines for adolescents.

No description available.

Recent global statistics estimate 20% of all cancer incidence could be prevented if Americans would modify their eating habits to increase fruit and vegetable intake to the minimum recommended level of five servings daily. Educational strategies to change eating behavior would benefit from a greater understanding of psychosocial and demographic factors related dietary behavior. Secondary analysis of a nationally representative survey of 2655 adults was completed to assess differences between low-income and high-income adults in psychosocial, demographic, and educational factors related to fruit and vegetable intake. Significant differences in self-efficacy, awareness/knowledge, and cost and availability of fruits and vegetables were found between the low-income and high-income groups. In the low-income group, 37% of the variance in total fruit and vegetable consumption was explained by psychosocial and demographic factors, with demographics, self-efficacy and awareness/knowledge being the most significant predictors. In the high-income group, 34% of the variance in total fruit and vegetable consumption was explained by psychosocial and demographic factors, with self-efficacy alone accounting for 14% of the variance. This research suggests that, regardless of income category, social cognitive factors, in particular self-efficacy and knowledge/awareness of the health message, are stronger predictors of fruit and vegetable consumption than are perceived barrier factors. Given the weaknesses of the survey instrument, the findings need to interpreted with caution. Policy inferences can be suggested from this research, but would need further research findings before implementation of nutrition policy recommendations. The implications of these research findings are that nutrition education interventions to increase fruit and vegetable consumption should be aimed at affecting those psychosocial factors that are predictive of behavior change. In particular, differences by income level between psychosocial, education, and behavior responses underscore the need for tailoring educational interventions by income group for greater impact. The most relevant psychosocial predictors of fruit and vegetable consumption in adults are self-efficacy, awareness/knowledge of the health message, social support, and weak intent. The most relevant demographic predictors were smoking status, educational level, and age. Income level appears to share variance with other demographic variables and should be explored in further research. / Ph. D.

<p>Obesity and overweight disproportionately impact Black American adolescent females—placing them at a lifetime of elevated physical health risks. Despite this burden, the literature that explores the contributors to obesity and overweight among Black American adolescent females remains limited and unclear. This dissertation aims to develop knowledge related to obesity and overweight in Black American adolescent females, by appraising the current understanding of factors that contribute to their obesity and overweight, and explicating the everyday social influences on dietary practices. The primary study conducted for this dissertation used a mixed method, multiple case study design to examine the mother, daughter, and other household contributors to Black American adolescent daughters’ everyday practices of food consumption, acquisition, preparation, and planning. Findings reveal the importance of understanding the complex and dynamic ways mothers and other household members contribute to a holistic view of everyday dietary practices among adolescent daughters. By deeply examining the nuanced ways the multiple cases varied, context-dependent knowledge essential to understanding the complicated health challenge of obesity was produced. Subsequently, recommendations are provided for health providers and scholars to more holistically approach and examine obesity—particularly among populations who are disproportionately affected.</p> / Dissertation

Introdução: Durante o processo de modificação de comportamentos de saúde, os indivíduos passam por diferentes fases, denominadas estágios de mudança de comportamento. O desenvolvimento de intervenções nutricionais específicas para cada estágio pode contribuir para a adoção de práticas alimentares saudáveis na adolescência. Objetivo: avaliar os estágios de mudança de comportamento e verificar sua relação com o consumo alimentar de adolescentes. Métodos: Trata-se de um estudo observacional transversal com adolescentes de escolas públicas de Piracicaba. Foram coletados dados demográficos, antropométricos, de maturação sexual e de consumo alimentar (questionário de freqüência). Realizou-se uma avaliação da percepção alimentar, por meio da comparação entre o consumo alimentar e a classificação individual do aspecto saudável da dieta. Os participantes foram classificados nos estágios de mudança de comportamento (pré-contemplação, contemplação, decisão, ação e manutenção) por meio de algoritmo específico. Resultados: Foram avaliados 390 adolescentes: média de idade de 12,4 anos, 46,4% meninos, 78,7% púberes e 21,1% com excesso de peso. Observou-se consumo médio de 3645kcal, sendo que 36,7% da amostra apresentou alto teor de lipídios na dieta. O consumo médio de frutas, hortaliças e doces foi de 2,3, 2,4 e 4,5 porções diárias, respectivamente. Mais de 44% dos adolescentes mostrou percepção errônea da dieta e não manifestou motivação para modificá-la. Cerca de 40% da amostra foi classificada no estágio de manutenção. Observou-se relação significativa entre os estágios de mudança e o consumo alimentar. Foi realizada uma reclassificação dos adolescentes nos estágios de mudança para identificar indivíduos com características semelhantes segundo o consumo e a percepção alimentares. Conclusão: A classificação dos adolescentes nos estágios de mudança, em associação com os dados de consumo e percepção alimentares, permitiram a identificação de grupos de risco por suas práticas alimentares inadequadas e pelo não-reconhecimento destas. Destaca-se a necessidade do desenvolvimento de intervenções nutricionais futuras direcionadas à população estudada. / Introduction: Over the process of health-related behavior change, people move through different steps called stages of change. The development of nutritional intervention tailored to each stage of change can contribute to the adoption of healthy dietary practices among adolescents. Objective: to evaluate the stages of change and their relationship with dietary intake among adolescents. Methods: Observational cross-sectional study with adolescents from public schools of Piracicaba. Demographic and anthropometric data, sexual maturation and dietary intake (food frequency questionnaire) were examined. Food perception was evaluated comparing dietary intake with self-rated diet. Stages of change classification (precontemplation, contemplation, preparation, action, maintenance) was assessed by a specific algorithm. Results: The sample included 390 adolescents: mean age of 12.4 years, 46.4% boys, 78.7% pubescents and 21,1% overweight. Mean daily energy intake was 3645kcal and 36,7% of adolescents had excessive intake of dietary fat. Average intake of fruits, vegetables and sweets were respectively 2.3, 2.4 and 4.5 portions per day. More than 44% of adolescents were unaware of their unfavourable dietary intake and were not interested in change it. About 40% of adolescents were assigned in maintenance stage. A significant relationship was observed between stages of change and dietary intake. Adolescents were re-classified into stages of change to identify individuals with similar characteristics according to their dietary intake and their food perception. Conclusion: The stage of change assignment, in association with dietary intake and food perception data, allowed the identification of risk groups, considering their inadequate dietary practices and the lack of awareness about them. It should be emphasize the necessity of the development of future nutritional intervention tailored to this population.

Doctor of Philosophy / Human Nutrition / Edgar Chambers IV / Understanding “why people eat what they eat” is important for improving the lives of people around the world by helping provide industrial and social solutions for people so that they may have greater pleasure and health from the foods they choose. The objectives of the research were to investigate motivations behind everyday meals and choices of different food groups using three different approaches incorporating two psychological perspectives: top-down and bottom-up. The first approach was the Eating Motivation Survey (TEMS) targeting the specific choices of foods and beverages people consumed at specific eating events (breakfast, mid-morning snack, lunch, mid-afternoon snack, dinner, and late-night snack). The second approach was the Food Choice Map (FCM) technique to explore motivations for individual food choices for all eating within a typical week. These two approaches employed the bottom-up process. The last approach used TEMS to investigate food choice directly for six eating occasions, without information about what were eaten specifically. This procedure demonstrated a top-down process because people first thought about their eating as a whole and then read through all TEMS scales to find the motivations that they consider "appropriate" for their answers. The first surveys were completed by 198 participants. The FCM interview was conducted on 100 respondents and the same respondents also participated in the last approach. Data were analyzed by Correspondence Analysis. Liking was the strongest motivation that drove people’s food choice. In addition, need and hunger, habits, price, and convenience were the other main motivations for breakfast, lunch, and dinner while health and weight control were found to be the main driving factors for mid-morning and mid-afternoon snacking. Late-night snacks were linked to pleasure and visual appeal. For dinner, people also were motivated most by variety seeking and traditional eating. Different food groups were also chosen with different motivations. Grain, pasta, meats and poultry were linked to convenience, variety seeking, traditional eating, and price while nuts, seeds, eggs and dairy were associated with need and hunger, health, and weight control. Findings from this project advanced and reinforced the knowledge about food choice and encouraged investigating food choice from different perspectives.

Introdução: Durante o processo de modificação de comportamentos de saúde, os indivíduos passam por diferentes fases, denominadas estágios de mudança de comportamento. O desenvolvimento de intervenções nutricionais específicas para cada estágio pode contribuir para a adoção de práticas alimentares saudáveis na adolescência. Objetivo: avaliar os estágios de mudança de comportamento e verificar sua relação com o consumo alimentar de adolescentes. Métodos: Trata-se de um estudo observacional transversal com adolescentes de escolas públicas de Piracicaba. Foram coletados dados demográficos, antropométricos, de maturação sexual e de consumo alimentar (questionário de freqüência). Realizou-se uma avaliação da percepção alimentar, por meio da comparação entre o consumo alimentar e a classificação individual do aspecto saudável da dieta. Os participantes foram classificados nos estágios de mudança de comportamento (pré-contemplação, contemplação, decisão, ação e manutenção) por meio de algoritmo específico. Resultados: Foram avaliados 390 adolescentes: média de idade de 12,4 anos, 46,4% meninos, 78,7% púberes e 21,1% com excesso de peso. Observou-se consumo médio de 3645kcal, sendo que 36,7% da amostra apresentou alto teor de lipídios na dieta. O consumo médio de frutas, hortaliças e doces foi de 2,3, 2,4 e 4,5 porções diárias, respectivamente. Mais de 44% dos adolescentes mostrou percepção errônea da dieta e não manifestou motivação para modificá-la. Cerca de 40% da amostra foi classificada no estágio de manutenção. Observou-se relação significativa entre os estágios de mudança e o consumo alimentar. Foi realizada uma reclassificação dos adolescentes nos estágios de mudança para identificar indivíduos com características semelhantes segundo o consumo e a percepção alimentares. Conclusão: A classificação dos adolescentes nos estágios de mudança, em associação com os dados de consumo e percepção alimentares, permitiram a identificação de grupos de risco por suas práticas alimentares inadequadas e pelo não-reconhecimento destas. Destaca-se a necessidade do desenvolvimento de intervenções nutricionais futuras direcionadas à população estudada. / Introduction: Over the process of health-related behavior change, people move through different steps called stages of change. The development of nutritional intervention tailored to each stage of change can contribute to the adoption of healthy dietary practices among adolescents. Objective: to evaluate the stages of change and their relationship with dietary intake among adolescents. Methods: Observational cross-sectional study with adolescents from public schools of Piracicaba. Demographic and anthropometric data, sexual maturation and dietary intake (food frequency questionnaire) were examined. Food perception was evaluated comparing dietary intake with self-rated diet. Stages of change classification (precontemplation, contemplation, preparation, action, maintenance) was assessed by a specific algorithm. Results: The sample included 390 adolescents: mean age of 12.4 years, 46.4% boys, 78.7% pubescents and 21,1% overweight. Mean daily energy intake was 3645kcal and 36,7% of adolescents had excessive intake of dietary fat. Average intake of fruits, vegetables and sweets were respectively 2.3, 2.4 and 4.5 portions per day. More than 44% of adolescents were unaware of their unfavourable dietary intake and were not interested in change it. About 40% of adolescents were assigned in maintenance stage. A significant relationship was observed between stages of change and dietary intake. Adolescents were re-classified into stages of change to identify individuals with similar characteristics according to their dietary intake and their food perception. Conclusion: The stage of change assignment, in association with dietary intake and food perception data, allowed the identification of risk groups, considering their inadequate dietary practices and the lack of awareness about them. It should be emphasize the necessity of the development of future nutritional intervention tailored to this population.

This study examined the association between level of physical activity and changes in dietary behaviors of 3,945 employees after a 10-week work-site physical activity program. Fifty-seven percent of the participants met the CDC/ACSM standard for physical activity sufficient for a health benefit. Physical activity was not significantly related to increased fruit and vegetable consumption, decreased dietary fat and calorie intake, and participants acquiring new nutrition skills. Physical activity was negatively associated with increased food label awareness. Participants who exercised sufficient for a health benefit were less likely to increase their food label awareness. Physical activity and dietary behaviors are generally not associated. Interventions to improve these behaviors should be behavior-specific.