The Effects Of Selected Food Properties and Environmental Factors On Ingestive Behavior And Physiological Responses In Healthy Adults

As the obesity epidemic continues, there is a great need to better understand the drivers of ingestive behavior. Food properties and environmental factors are two components of ingestive behavior that merit further examination. Therefore, the main objectives of this dissertation were to determine: 1) whether a lower-sugar afternoon hummus snack compared with a common higher-sugar snack or no snack improves diet quality, appetite, satiety, and glycemic control in healthy adults; 2) whether snack availability, package size, and variety influence snacking behavior in healthy adults; and 3) the mechanisms of action of a superabsorbent hydrogel device through the investigation of its effects on appetitive sensations, eating behavior, energy intake, and fecal excretion of fat and total energy.

This dissertation is organized into chapters that consist of a dissertation rationale, a related literature review, manuscripts (published or under-review) from three clinical trials, and a discussion of future research directions. Chapter 2 consists of a review of relevant food properties and environmental factors that influence ingestive behavior. Chapter 3 examines whether a lower-sugar afternoon hummus snack compared with a common higher-sugar snack or no snack improves diet quality, appetite, satiety, and glycemic control in healthy adults. Chapter 4 examines whether snack availability, package size, and variety influence snacking behavior in healthy adults. Chapter 5 examines the mechanisms of action of a superabsorbent hydrogel device through the investigation of its effects on appetitive sensations, eating behavior, energy intake, and fecal excretion of fat and total energy. Chapter 6 summarizes the main findings and presents considerations for future research.

Collectively, the findings from this dissertation demonstrate: 1) the daily consumption of a low-sugar afternoon hummus snack might be a useful dietary strategy to improve diet quality, selected indices of appetite, and glycemic control; 2) providing participants with free access to highly palatable snack foods substantially increased snack intake when compared to habitual snacking behaviors, larger packages of snacks led to significantly greater total snack intake and dessert snack intake than smaller packages of snacks, and greater snack variety resulted in greater intake of fruits and vegetables but had no effect on total snack intake; and 3) a superabsorbent hydrogel device does not exert its weight loss effects through changes in appetitive sensations, energy intake, or fecal excretion of energy or fat. Thus, this work suggests that selected food properties and environmental factors differentially influence ingestive behavior in healthy adults. The included studies provide an improved understanding of the field of ingestive behavior, but future studies are needed to further explore this complex, evolving process.