This study characterized associations of restraint with selected physical, lifestyle, personality and menstrual cycle characteristics in female university students. The survey instrument, distributed to 1350 women, included standardized questionnaires (Three-Factor Eating Questionnaire, Perceived Stress Scale and Rosenberg's Self-esteem Scale), and assessed weight and dieting history, exercise, lifestyle characteristics, menstrual cycle characteristics and whether participants were following vegetarian diets. Among the 596 respondents included in the analysis (44%), women with high (n=145), medium (n=262) or low (n=189) restraint had similar ages, heights and weights. Despite this, compared to women with low scores, those with high scores exercised more (4.6±5.3 vs. 3.2±3.5 h/wk), were more likely to be vegetarian (14.5 vs. 3.7%), have a history of eating disorders (13.7 vs. 1.2%), be currently trying to lose weight (80.3 vs. 15.3%), report irregular menstrual cycles (34.7 vs. 17.0%), and have scores reflecting lower self-esteem and higher perceived stress. Menstrual irregularity was an independent predictor of restraint score, and restraint score was the only variable to differentiate women with regular and irregular menstrual cycles. We conclude that women with high restraint may use a combination of behavioral strategies for weight control, and differ from women with low restraint scores in personality characteristics and weight history. Some of these behaviors or characteristics may influence menstrual function.
Many women consciously try to limit their food intake to achieve or maintain a desired body weight. This is referred to as dietary restraint or cognitive dietary restraint, a type of eating behavior governed by cognitive processes rather than by physiological mechanisms such as hunger and satiety (Gorman & Allison, 1995). Although several scales to assess dietary restraint exist, the Restraint Factor scale of the Three-Factor Eating Questionnaire (TFEQ; Stunkard & Messick, 1985) is considered to be robust and have good psychometric properties (Gorman & Allison, 1995). Typically, women with high scores for restraint are very aware of the amount and type of food they consume although reports vary as to whether their energy intakes are actually lower than those of women with low restraint scores (Barr et al., 1994b, McLean et al., 2001a, McLean et al., 2001b, Schweiger et al., 1992, Smith et al., 1998 and Tuschl et al., 1990a).
Previous studies have found women with high restraint scores to be generally similar to those with low restraint scores in terms of age, height, weight and Body Mass Index (BMI) (Barr et al., 1994a, Barr et al., 1994b, Laessle et al., 1989a, Pirke et al., 1990, Schweiger et al., 1989 and Van Loan and Keim, 2000). Where a difference has been found has been in menstrual cycle, and particularly ovulatory, characteristics. Several studies have reported that women with high restraint scores were more likely to experience disturbances of ovulation including a higher proportion of anovulatory cycles and short luteal phase or cycle lengths (Barr et al., 1994a, Barr et al., 1994b, Lebenstedt et al., 1999 and Schweiger et al., 1992).
Women with varying scores for dietary restraint have previously been characterized according to several physical and lifestyle variables which may increase physical or psychological stress and consequently impact on the menstrual cycle (Barr et al., 1994a, Barr et al., 1994b, Laessle et al., 1989a, Schweiger et al., 1992 and Tuschl et al., 1990b). Unfortunately, many of these studies had small numbers of subjects or used exclusion criteria, which may have limited the findings to a select group. Accordingly, the purpose of this study was to characterize a large, unselected group of university women with regard to dietary restraint, and to assess whether differences existed among women categorized as having low, medium or high restraint in terms of eating behaviors, lifestyle habits, selected personality characteristics and menstrual regularity.
