Background: According to the Centers for Disease Control and Prevention (CDC), over one-third of US adults are obese. In order to assess causes of and treatments for obesity, researchers have evaluated a number of processes underlying health-related behaviors, one of which is delay discounting. Delay discounting is a cognitive process that describes the phenomenon by which individuals discount the value of a future reward compared to the value of an immediate reward. Researchers have associated delay discounting with drug addiction, alcoholism, and cigarette smoking. More recently, delay discounting has been studied with regards to health-related behaviors, such as body weight management, food intake, glucose control, and physical activity. While a number of studies have concluded that obese individuals tend to be greater discounters, the relationship between delay discounting and various health-related behaviors beyond smoking and drug use remains unclear. The purpose of this study is to evaluate the relationship between delay discounting and diet quality, glucose tolerance, physical activity, and fasting vs. non-fasting conditions. Methods: Sixty-five males (n=20) and females (n=45) were recruited for the present study. Participants completed two lab sessions: one under non-fasting conditions, and one under fasting conditions which involved measurements of body mass and composition, blood pressure, blood glucose, blood lipids, and health-related questionnaires. Delay discounting and food purchase tasks were completed at both visits. Participants were asked to complete a four-day food intake record and wear a physical activity monitor for four days. Results: Lower rates of discounting were found in those who consumed more total vegetables, and lower food reinforcement was observed in those who spent less time sedentary and more time physically active, had greater dietary Restraint, and had a lower resting heart rate. There were no significant differences between discounting rates and food reinforcement across fasting and non-fasting conditions. / Master of Science / More than one-third of US adults are obese. Obesity brings with it a number of chronic health conditions as well as the financial burden of increased healthcare costs. There are a multitude of treatment methods for obesity, and researches have evaluated many aspects of behaviors that contribute to obesity. Decision-making processes are an important factor related to management of body weight as well as general health. One field of study concerned with decision-making is called behavioral economics, and it includes the concept of delay discounting. Delay discounting is a cognitive process by which individuals tend to discount the value of future rewards in favor of more immediate rewards. This behavior has been associated with drug use and addiction, alcoholism, and cigarette smoking, as well as a number of other psychological or social parameters. More recently, research has connected delay discounting with health-related factors such as body weight management, glucose control, physical activity, and diet quality. A number of studies have concluded that obese individuals tend to be greater discounters, meaning that they prefer immediate rewards rather than delaying gratification for future rewards, however the relationship between delay discounting and various health-related behaviors remains unclear. The purpose of this study is to evaluate the relationship between delay discounting and diet quality, glucose tolerance, physical activity, and fasting vs. nonfasting conditions. Methods: Sixty-five males (n=20) and females (n=45) were recruited for the present study. Participants completed two lab sessions: one under non-fasting conditions, and one under fasting conditions which involved measurements of body mass and composition, blood pressure, blood glucose, blood lipids, and health-related questionnaires. Delay discounting and food purchase tasks were completed at both visits. Participants were asked to complete a four-day food intake record and wear a physical activity monitor for four days. Results: Lower rates of discounting were found in those who consumed more total vegetables, and lower food reinforcement was observed in those who spent less time sedentary and more time physically active, had greater dietary Restraint, and had a lower resting heart rate. There were no significant differences between discounting rates and food reinforcement across fasting and non-fasting conditions.

Energy intake (EI) and energy expenditure (EE) across the menstrual cycle (MC), while considering body adiposity, have not been previously evaluated in the same individuals. This study mainly examined the variations in energy balance (EB) across MC. Seventeen women (Body fat-DXA:28.5%) participated in three identical sessions during distinct phases of the MC: Early-follicular, Late-follicular/ovulation and Mid-luteal (confirmed by basal temperature and sex-steroid hormones). EI, resting metabolic rate (RMR), physical-activity EE (PAEE), severity of PMS, leptin and relative-reinforcing value (RRV) of preferred foods were measured during each phase. No differences in body fat, EI, RMR, PAEE, leptin and RRV of food were noted across MC. Trends were noted in preferred snack (p=0.06) and combined snack/fruit (p=0.06) intakes, while differences were noted in severity of PMS (p<0.05) across phases. Changes in EB across the MC were not noted. PMS was more severe, and preferred snack and combined snack/fruit intakes were slightly higher during mid-luteal phase.

Energy intake (EI) and energy expenditure (EE) across the menstrual cycle (MC), while considering body adiposity, have not been previously evaluated in the same individuals. This study mainly examined the variations in energy balance (EB) across MC. Seventeen women (Body fat-DXA:28.5%) participated in three identical sessions during distinct phases of the MC: Early-follicular, Late-follicular/ovulation and Mid-luteal (confirmed by basal temperature and sex-steroid hormones). EI, resting metabolic rate (RMR), physical-activity EE (PAEE), severity of PMS, leptin and relative-reinforcing value (RRV) of preferred foods were measured during each phase. No differences in body fat, EI, RMR, PAEE, leptin and RRV of food were noted across MC. Trends were noted in preferred snack (p=0.06) and combined snack/fruit (p=0.06) intakes, while differences were noted in severity of PMS (p<0.05) across phases. Changes in EB across the MC were not noted. PMS was more severe, and preferred snack and combined snack/fruit intakes were slightly higher during mid-luteal phase.

Energy intake (EI) and energy expenditure (EE) across the menstrual cycle (MC), while considering body adiposity, have not been previously evaluated in the same individuals. This study mainly examined the variations in energy balance (EB) across MC. Seventeen women (Body fat-DXA:28.5%) participated in three identical sessions during distinct phases of the MC: Early-follicular, Late-follicular/ovulation and Mid-luteal (confirmed by basal temperature and sex-steroid hormones). EI, resting metabolic rate (RMR), physical-activity EE (PAEE), severity of PMS, leptin and relative-reinforcing value (RRV) of preferred foods were measured during each phase. No differences in body fat, EI, RMR, PAEE, leptin and RRV of food were noted across MC. Trends were noted in preferred snack (p=0.06) and combined snack/fruit (p=0.06) intakes, while differences were noted in severity of PMS (p<0.05) across phases. Changes in EB across the MC were not noted. PMS was more severe, and preferred snack and combined snack/fruit intakes were slightly higher during mid-luteal phase.

Energy intake (EI) and energy expenditure (EE) across the menstrual cycle (MC), while considering body adiposity, have not been previously evaluated in the same individuals. This study mainly examined the variations in energy balance (EB) across MC. Seventeen women (Body fat-DXA:28.5%) participated in three identical sessions during distinct phases of the MC: Early-follicular, Late-follicular/ovulation and Mid-luteal (confirmed by basal temperature and sex-steroid hormones). EI, resting metabolic rate (RMR), physical-activity EE (PAEE), severity of PMS, leptin and relative-reinforcing value (RRV) of preferred foods were measured during each phase. No differences in body fat, EI, RMR, PAEE, leptin and RRV of food were noted across MC. Trends were noted in preferred snack (p=0.06) and combined snack/fruit (p=0.06) intakes, while differences were noted in severity of PMS (p<0.05) across phases. Changes in EB across the MC were not noted. PMS was more severe, and preferred snack and combined snack/fruit intakes were slightly higher during mid-luteal phase.