The Effect of Psychological Stress and Eating Attitudes on the Physiologcial Resonpse to Food Intake in Exercising Women

Open Access
Author:
Vesperman, Kathryn Rose
Area of Honors:
Kinesiology
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Nancy Williams, Thesis Supervisor
  • Stephen Jacob Piazza, Honors Advisor
Keywords:
  • eating attitudes and behaviors
  • physiological response to a meal
  • psychological stress
Abstract:
Physiological responses to psychological stress can have a number of detrimental effects on the human body. Psychometric and biological measures reflective of psychological stress have been significantly related to cardiovascular disease and obesity [1, 2]. How an individual experiences stress can become manifest in one’s attitudes toward eating and their eating behaviors [3, 4]. A high degree of control over eating or propensity to restrict food intake may be thought of as a stress related behavior [3]. The impact of psychological stress and attitudes toward food intake that are stress related may also impact the physiological response to food intake. In turn, because the physiological response to food intake represents a component of energy balance, it is important to understand how psychological stress, eating attitudes, and the physiological response to food intake are related. Exercising women have been shown to display a range of eating attitudes that include severe restriction of caloric intake [5]. Although links have been demonstrated between measures of psychological stress and eating attitudes, no studies have comprehensively explored these relationships, particularly in exercising women. Moreover, work suggesting a relation between psychological stress and the physiological response to eating is even more limited [6, 7]. The purpose of this study was therefore to explore the relations between measures of psychological stress, eating attitudes and behaviors, and the physiological response to food intake. We hypothesized that indices of psychological stress and eating attitudes would be directly related to the cardiovascular and energetic response to a meal, such that indications of greater stress or poorer attitudes toward food and body image would be associated with higher measures of heart rate, blood pressure, and the thermic effect of a meal. Eight healthy, weight stable females aged 18-34 years that participated in regular aerobic exercise were recruited for the study. Prior to the test condition day subjects’ dietary intake was controlled. During the test condition, subjects were given a standardized 700 kcal mixed macronutrient meal and the thermic effect of food as well as heart rate and blood pressure were measured for four hours after the meal. The State Anxiety Inventory was found to have a significant negative correlation to both the disinhibition subscale of the Three Factor Eating Questionnaire (R= -0.872; p=0.005) and the anger/frustration subscale of the Emotional Eating Scale (R= -0.728; p= 0.04) and a positive correlation with the average heart rate adjusted for resting over the testing period (R= 0.781; p= 0.022). The Perceived Stress Scale and Daily Stress Inventory were found to be positively correlated with the +175time point heart rate that was adjusted for resting values (R= 0.819, p=0.013 and R=0.812; p=0.026, respectively). Low self esteem as measured from the Eating Disorder Inventory- 3 was the only eating attitudes and behavior questionnaire that exhibited a statistically significant relationship with the physiological response to a meal (R= -0.762; p=0.046). It is concluded that in exercising women scores on eating attitudes and behavior questionnaires are not as extreme as those in anorexic subjects and thus did not show similar results with respect to the energetics of food intake as those seen in that population [6]. However, the relationship between psychological stress measures and the cardiovascular response to a meal suggests that this response to a meal may be indicative of a chronically stressed individual. More research in these areas with larger sample size is needed to corroborate these results.