High Dietary Cognitive Restraint, Independent of Disinhibition, is Associated with Lower Energy Availability in Exercising Women

Open Access
Author:
Rickard, Ashley Deanna
Area of Honors:
Kinesiology
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Nancy Williams, Thesis Supervisor
  • Stephen Jacob Piazza, Honors Advisor
Keywords:
  • Cognitive Restraint
  • Disinhibition
  • Energy Availability
  • Female Athlete Triad
Abstract:
Subclinical disordered eating behavior, as indicated by a high dietary cognitive restraint (CR), is highly prevalent in premenopausal exercising women with chronic energy deficiency and acts as a key factor in promoting the development of the Female Athlete Triad. Disinhibition is a counter-regulatory response to the restriction of food intake and represents an absence or reversal of inhibition. The effect that disinhibition has on energetic characteristics alongside CR has yet to be examined in exercising women. The purpose of this study is to compare energetic characteristics in exercising women when categorized by CR and disinhibition status. We hypothesized that : (1) The High CR + Normal Disinhibition group would have a lower energy intake and EA compared to the High CR + High Disinhibition group; (2) The High CR + Normal Disinhibition group would have lower resting energy expenditure REE, corroborated by lower TT3 and higher ghrelin, compared to the High CR and High Disinhibition group. This was a cross-sectional study that included data in 85 women who were 23±4 years old, weighed 57.6±5.9 kg, had a VO2 max of 47±7mL/kg/min, and had a percent body fat of 25±5. Subjects were retrospectively characterized by cognitive restraint and disinhibition scores into three groups: (1) High CR + High Disinhibition (n=14), (2) High CR + Normal Disinhibition (n=27), and (3) Normal CR + Normal Disinhibition (n=44). CR and disinhibition scores were obtained from the Three Factor Eating Questionnaire. We operationally defined a high CR score as ≥11; whereas a normal CR score was <11. We operationally defined a high disinhibition score as ≥8; whereas a normal disinhibition score was <8. Body composition was measured using dual energy x-ray absorptiometry. Energy intake (EI) was determined using 3 day diet logs. Energy availability (EA) was defined as (EI - purposeful exercise calories (EEE))/kg lean body mass (LBM) and calculated for a 7 day period. Resting energy expenditure (REE) was measured using a ventilated hood system and we computed the ratio of the actual REE/predicted REE (REE/pREE) with predicted REE derived from the Harris Benedict equation. Fasting blood samples were obtained twice during the study period and were pooled and assayed for triiodothyronine (T3) and ghrelin concentrations. EA was significantly lower in the High CR + Normal Disinhibition group compared to the Normal CR + Normal Disinhibition group (34.6 kcal/kg LBM vs. 43.5 kcal/kg LBM, p=0.005). Whereas, there were no significant differences in EA (p>0.05) between the High CR + High Disinhibition group and the other groups. Measures of EI revealed no significant differences (p=0.705) between women with High CR + Normal Disinhibition and those with High CR + High Disinhibition. However, women with Normal CR + Normal Disinhibition consumed significantly higher EI compared to High CR + Normal Disinhibition and High CR + High Disinhibition (2003 kcal/d vs. 1740 kcal/d and. 1677 kcal/d, p<0.05). There were no significant differences (p>0.05) between groups for EEE and lean body mass. Our findings demonstrated no significant differences (p>0.05) in REE, REE/pREE, T3 and ghrelin concentrations between groups. CR score was negatively correlated with EA (r=-0.351, p= 0.001), EI (r=-0.379, p<0.001) and REE/pREE (r=-0.255, p=0.018). Disinhibition score was not significantly associated (p>0.05) with any of the EA parameters. However, disinhibition score was positively correlated with body mass (r=0.283, p=0.008) and negatively correlated with total exercise volume (r=-0.248, p=0.027). When discriminating solely by CR score, both EA and EI were significantly lower in exercising women with high CR (35.4 kcal/kg LBM and 1719 kcal/d, respectively) vs. women with normal CR (43.7 kcal/kg and 2031 kcal/d, respectively). These findings suggest an association between CR score and EA, primarily via EI, in exercising women. Women with a high CR and normal disinhibition have a lower EA compared to those with normal CR and disinhibition. However, our findings demonstrate that disinhibition score does not further discriminate these women in terms of EA and EI. Thus, the CR subscale alone may be a better psychometric indicator of EA in exercising women than the combination of CR and disinhibition.