Construct validity of the Three-Factor Eating Questionnaire: flexible and rigid control subscales.

This study investigated the construct validity of two dietary restraint subscales, flexible control (FC) and rigid control (RC), identified by Westenhoefer (1991; Appetite, 16, 45-55) as a subset of the restraint scale items from the Three-Factor Eating Questionnaire (TFEQ, Stunkard & Messick. [1985]. Journal of Psychosomatic Research, 29, 71-83). The subjects were 31 women on long-term personality disorder units. Based on the Structured Clinical Interview for DSM-III-R (SCID), 68% has past anorexia and/or bulimia diagnoses and 94% were borderline. The subjects completed the TFEQ and supplied weight and height data for body mass index (BMI) calculations. The results supported the validity of the two restraint constructs by showing that FC was inversely related to BMI and predicted an anorexia diagnosis. In contrast, RC directly predicted BMI when tested concurrently with FC. RC was also more associated with a history of bulimia and problems with weight fluctuations than FC was. Thus, the FC-RC distinction was valid and useful in this population of women.