• JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
 
  Bookmark and Share
 
 
Master's Dissertation
DOI
10.11606/D.59.2017.tde-24042017-112146
Document
Author
Full name
Raquel Lunardi Baccetto
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
Ribeirão Preto, 2016
Supervisor
Committee
Almeida, Sebastião de Sousa (President)
Costa, Telma Maria Braga
Jordao Junior, Alceu Afonso
Riul, Tania Regina
Title in Portuguese
Efeitos de um modelo de oferta e retirada de dieta de cafeteria sobre o comportamento alimentar e ansiedade em ratas
Keywords in Portuguese
Adicção alimentar
Adolescência
Ansiedade
Compulsão alimentar
Dieta de cafeteria
Fêmeas
Abstract in Portuguese
A incidência global de obesidade tem aumentado nas últimas décadas e o consumo excessivo de alimentos industrializados ricos em açúcar e gordura está entre suas principais causas. Pesquisas recentes têm mostrado que estes alimentos desencadeiam mecanismos neurais e comportamentos semelhantes à adicção a drogas. Sabe-se que hábitos e preferências alimentares de adultos são adquiridos na infância, mas intervenções efetivas para prevenção da obesidade e suas comorbidades em crianças e adolescentes ainda constituem um desafio para a saúde pública. O objetivo do presente estudo foi avaliar os efeitos do consumo de dieta de cafeteria e retirada desta no comportamento alimentar, peso corporal, perfil lipídico, regularidade do ciclo estral, e comportamento de ansiedade e motivação. Ratas Wistar tiveram acesso limitado a itens alimentares de consumo humano de alta densidade energética por quatro semanas, ao final das quais foi realizada a retirada da dieta experimental de duas maneiras: para um grupo total e brusca, e para outro gradual durante uma semana. Após essa retirada, que simula dietas humanas de restrição, as ratas foram submetidas a testes comportamentais para avaliar ansiedade (labirinto em cruz elevado), e motivação para restabelecimento do acesso à dieta de cafeteria (modelo de restabelecimento). O grupo submetido à dieta de cafeteria apresentou maior consumo de gorduras totais e saturadas (p<0,05), e menor consumo de proteínas totais e fibras (p<0,05). Apesar disso, o consumo energético diário entre os grupos não atingiu diferença estatisticamente significativa, assim como o peso corporal das ratas. Após retirada da dieta de cafeteria, o consumo energético foi reduzido significativamente, porém, não acompanhado de perda de peso. Houve diferença significativa no perfil lipídico, sendo que ratas do grupo Cafeteria Sem Retirada tiveram os maiores valores de colesterol total e colesterol LDL (p<0,05). As ratas que sofreram retirada da dieta de cafeteria tiveram seus valores de colesterol similares às alimentadas somente com ração. A retirada completa da dieta de cafeteria e consequente diminuição do consumo energético foi responsável por irregularidade no ciclo estral das ratas. Os resultados no labirinto em cruz elevado não atingiram diferença estatisticamente significativa. O grupo Ração passou mais tempo no lado claro (p<0,05), conforme mostrado pelo teste de restabelecimento. A oferta limitada, de curto prazo, pós-desmame da dieta de cafeteria foi efetiva no desenvolvimento de compulsão alimentar em ratas adolescentes, porém sem evidências de vício alimentar. É provável que a obesidade seja condição necessária para o vício. Esperamos que os resultados deste estudo contribuam para o conhecimento da relação entre qualidade da dieta e comportamento alimentar e de adicção em ratas adolescentes.
Title in English
Effects of a model of cafeteria diet supply and withdrawal on eating patterns and anxiety-like behavior in female rats
Keywords in English
Adolescence
Anxiety.
Binge eating disorder
Cafeteria diet
Females
Food addiction
Abstract in English
The global incidence of obesity has steadily risen in the last decades and the excessive intake of industrialized food rich in sugar and fat is among its main causes. Recent researches have shown that these foods activate neural mechanism and behaviors similar to what is seen with drug addiction. It is known that adults eating habits and preferences are generally established during childhood, but effective preventive measures against obesity and its comorbities in children and adolescents are still a current public health challenge. The goal of the present study was to evaluate the effects of a cafeteria diet intake and withdrawal on eating behavior, body weight, lipid profile, estrous cycle regularity, and anxiety-like and motivational behavior. Female Wistar rats had limited access to energy-dense food items typically consumed by humans for four weeks, at the end of which, withdrawal from this diet occurred in one of two ways: for a group withdrawal was abrupt and total, and for another group, gradual for one week. After withdrawal, which attempts to mimic human restrictive dieting, we evaluated rats anxiety-like behavior through the elevated plus maze, and their motivation to reinstate access to the cafeteria diet through a reinstatement model. Daily energy intake between groups did not reach significant difference, as well as their body weight. Cafeteria fed rats did gain weight at a faster pace, and had a significant greater intake of total and saturated fat, and sodium (p<0.05); and a significantly lower intake of proteins and fibers (p<0.05). Groups that underwent withdrawal reduced their caloric intake significantly, but there was no weight loss. Rats with continuous access to cafeteria diet also had higher levels of total and LDL cholesterol (p<0.05), and rats from withdrawal groups had their cholesterol levels similar to chow-only animals. The total withdrawal of the cafeteria diet and resulting lower energy intake were also responsible for estrous cycle irregularities. There was no significant difference in rats performance in the EPM test. Chow only rats spent significantly more time in an aversive setting in order to gain access to an item from the cafeteria diet (p<0.05). The limited, short term, post-weaning offer of a cafeteria diet was effective in developing compulsive eating disorder, but without signs of food addiction. It is likely that obesity is precedent to the development of addiction. We expect that the results from this project contribute to the ongoing discussion and investigation on eating and addiction behavior in female adolescents rats.
 
WARNING - Viewing this document is conditioned on your acceptance of the following terms of use:
This document is only for private use for research and teaching activities. Reproduction for commercial use is forbidden. This rights cover the whole data about this document as well as its contents. Any uses or copies of this document in whole or in part must include the author's name.
MESTRADO.pdf (14.86 Mbytes)
Publishing Date
2017-09-04
 
WARNING: Learn what derived works are clicking here.
All rights of the thesis/dissertation are from the authors
CeTI-SC/STI
Digital Library of Theses and Dissertations of USP. Copyright © 2001-2020. All rights reserved.