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Snacking, Childhood Obesity, and Colon Carcinogenesis.

Xu, Jinyu, Xu
http://rave.ohiolink.edu/etdc/view?acc_num=osu1461245235

Abstract Details

2016, Doctor of Philosophy, Ohio State University, Nutrition Program, The Ohio State University.
Childhood obesity has been a serious problem in both developed and developing countries. Efforts at all levels of society have been made to reduce childhood obesity rates in the U.S., yet no significant reductions have been achieved over the past 10 years. Transitions in snacking over the past 30 years has been proposed as a risk factor for the increase in childhood obesity rates in the U.S. However, conflicting findings were reported by independent research groups. Recently, the long-term impacts of childhood obesity on chronic disease development have been acknowledged. Moreover, energy restriction has been established as an effective approach to lose weight and to reverse the harmful effects of obesity on chronic diseases in both human and animal models. However, the influences of lifetime transitions in energy intake on body weights as well as risks of cancer have not been fully examined. In the present research project, both risk factors of childhood obesity and its impacts on colon carcinogenesis have been investigated. To identify potential dietary risk factors for childhood obesity, 24-hour dietary recall data have been analyzed among a nationally representative population of U.S. children from ages 2-18. Among the selected population, snacking contributed more than 27% to total dietary fiber intake, while the fiber density in snacking was approximately 7 gm/1,000 kcal. Younger children (2-11 years old) had more fiber from snacking, compared to older children (12-18 years old), yet the fiber density in snack foods remained the same. The inverse association between fiber density in snacking and the risk of being overweight/obese was limited to older children (12-18 years old, OR = 0.770, 95%CI: 0.59-0.998, p = 0.048), while the association among younger children was positive, but not statistically significant. To study the influences of lifetime alterations in energy intake on body weight and colon carcinogenesis, nine combinations of dietary energy intake were incorporated in a murine model of colon cancer. The observed detrimental impacts of a high fat diet on colon cancer risk were consistent with previous studies. The present project expands the understanding of energy restriction on colon carcinogenesis in that the protective effects of energy restriction on colon cancer development were limited to intervention in later life, while early life exposure to energy restriction increased the risk of colon cancer, especially with the combination of a high fat diet in later life. Colonic mucosal bacteria are proposed as a mediator of the long-term impacts of energy intake on body weight and colon carcinogenesis. Although an actual causal relationship has not been established, in this project the significant lingering impacts of dietary energy intake on gut microbiota structure and the relative abundances of certain phyla and genera supported the hypothesis that gut microbiota may be a mechanistic component underlying the causal pathway between diet and colon carcinogenesis. The present project not only identified a risk factor for childhood obesity to facilitate development of effective prevention strategies, but also expanded our knowledge of dietary energy intake in childhood as an important player in obesity development and colon carcinogenesis. Findings in this project emphasize the significant role of the gut microbiota on diet and colon health.
Susan Olivo-Marston (Advisor)
Steven Clinton (Committee Member)
Randall Harris (Committee Member)
Micheal Bailey (Committee Member)
156 p.
Epidemiology; Nutrition
Childhood obesity; snacking; dietary intake; colon cancer; gut microbiota; high-fat diet; energy restriction; animal model

Recommended Citations

Citations

  • Xu, Xu, J. (2016). Snacking, Childhood Obesity, and Colon Carcinogenesis. [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1461245235

    APA Style (7th edition)

  • Xu, Xu, Jinyu. Snacking, Childhood Obesity, and Colon Carcinogenesis. . 2016. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1461245235.

    MLA Style (8th edition)

  • Xu, Xu, Jinyu. "Snacking, Childhood Obesity, and Colon Carcinogenesis. ." Doctoral dissertation, Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1461245235

    Chicago Manual of Style (17th edition)

osu1461245235
257
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This open access ETD is published by The Ohio State University and OhioLINK.