Award Date

8-1-2020

Degree Type

Thesis

Degree Name

Master of Arts (MA)

Department

Psychology

First Committee Member

Kristen Culbert

Second Committee Member

Andrew Freeman

Third Committee Member

Murray Millar

Fourth Committee Member

Petery Gray

Number of Pages

67

Abstract

Objective: Animal and human data indicate that fluctuations in ovarian hormones (e.g., estrogen and progesterone) across the estrus/menstrual cycle drive changes in eating behavior. Post-ovulatory phases (i.e., mid-luteal and pre-menstrual in women) correspond to distinct ovarian hormone profiles (i.e., low estradiol or high estradiol coupled with high progesterone) that are known to have stimulatory effects on eating behavior and have been associated with increased risk for emotional eating and binge eating. Nonetheless, other specific components of dysregulated eating (e.g., preoccupation with food, loss of control over eating) that are related to and/or prospectively predict the development of clinical binge eating episodes have yet to be examined. Determining which specific features of dysregulated eating are impacted by hormonal shifts across the menstrual cycle could aid in elucidating the etiologic effects of ovarian hormones on eating disorders. This study aimed to address this gap by examining the fluctuation of several forms of dysregulated eating in a new sample of women. Method: Participants were 20 normal-weight women from the community (age 18-45) who completed multiple daily measures over one menstrual cycle (~30 days). Menstrual cycle phases were determined from a range of indicators: self-report onset of menses, basal body temperature, and urine hormone test strips. Several types of dysregulated eating symptoms (e.g., loss of control over eating, external eating, emotional eating, preoccupation with food, and intense desire/cravings to eat) were assessed each evening using well-validated questionnaires that were adapted for daily reports. Daily levels of negative affect were assessed using the Positive and Negative Affect Schedule (PANAS). Height/weight measurements were taken at the baseline and final appointments and used to calculate average Body Mass Index (BMI) across the cycle. Statistical Analyses: Consistent with prior studies, five-day rolling averages were computed for all dysregulated eating scores and this adjusted daily score was converted to within-person z-scores. Repeated-measures Analysis of Variance (ANOVA) and Covariance (ANCOVA) were then used to examine mean differences in levels of dysregulated eating symptoms across the four menstrual cycle phases (i.e., follicular vs. ovulatory vs. mid-luteal vs. pre-menstrual) and using pre-ovulatory (follicular/ovulatory) versus post-ovulatory (mid-luteal/pre-menstrual) comparisons. All cycle phase analyses adjusted for average BMI and phase levels of negative mood to ensure that changes in dysregulated eating occur above and beyond the effects of BMI and negative affect. Results: There was minimal evidence of cycle phase differences on most dysregulated eating symptoms. When cycle phase effects were detected, the dysregulated symptoms (e.g., external eating, intense desire to eat, emotional eating) appeared to be most elevated in the pre-ovulatory period (e.g., follicular phase) relative to the post-ovulatory period (i.e., midluteal or premenstrual phases) – a pattern that is opposite of prior research. Further, these phase-differences in levels of dysregulated eating were no longer significant once analyses adjusted for BMI and negative affect. Discussion: Findings from this study contrast with prior research that has documented post-ovulatory (midluteal and/or premenstrual phases), rather than pre-ovulatory, increases in eating behavior. While the observed pre-ovulatory increases in dysregulated eating symptoms seem to be largely accounted for by negative affect and BMI, the factors contributing to between-study replication of phase differences remain unclear. It is suspected, however, that methodological issues (e.g., lack of randomization of the start phase of the study) may have played a role. These findings highlight the importance of carefully considering several methodological issues when conducting menstrual cycle research.

Keywords

Binge Eating; Eating Disorder; Menstrual Cycle; Ovarian Hormones

Disciplines

Clinical Psychology | Psychology

File Format

pdf

File Size

3700 KB

Degree Grantor

University of Nevada, Las Vegas

Language

English

Rights

IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

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