This study investigated the relationship between dietary restraint (DR) and osteoporosis-related knowledge and beliefs in college women and men. A total of 517 university students completed measures of osteoporosis knowledge, perceived susceptibility to and severity of osteoporosis, barriers to and benefits of calcium and exercise, health motivation, exercise and calcium self-efficacy, and DR. Two MANOVAs were conducted to examine differences between high and low dietary restrainers on osteoporosis beliefs and knowledge. For women, HR scored higher on perceived susceptibility to, and severity of, osteoporosis, calcium barriers, and health motivation; for men, HR scored lower on exercise benefits. These results suggest that DR may be related to osteoporosis beliefs and knowledge differently for men and women.
Osteoporosis (OP) is a disease of low bone mass, which increases the risk for fractures (National Institutes of Health [NIH], 2007). It is estimated that 1 in 2 women and 1 in 4 men over age 50 will experience an osteoporotic-related fracture (NIH, 2007). Attainment of peak bone mass is critical for the prevention of OP, with lifestyle factors such as exercise and calcium consumption identified as important modifiable factors for osteoporosis prevention (NIH, 2007).
One theoretical model which explains engagement in preventive behaviors is the Health Belief Model (HBM; Rosenstock, Strecher, & Becker, 1988). The HBM predicts that beliefs about specific illnesses and their preventive health behaviors impact the likelihood of performing these behaviors. These beliefs include: perceived threat (a function of perceived susceptibility to and perceived severity of the condition); relative cost of the behavior (difference between perceived barriers to and perceived benefits of performing the behavior); and modifying factors including demographic, psychosocial, and structural (e.g., knowledge) variables. Self-efficacy and general health motivation have been added to the original model (Rosenstock et al., 1988).
Research examining exercise and/or calcium consumption using the HBM has been equivocal (Ali, 1996, Kasper et al., 1994 and Wallace, 2002). When support for theoretical suppositions has been found, the strongest predictor of calcium consumption and exercise has been self-efficacy, with barriers to calcium intake and exercise also predicting behavior in college women (Ali, 1996 and Wallace, 2002). By contrast, perceived susceptibility and severity have received little support as predictors of these behaviors in college women (Wallace, 2002), and these beliefs have not been examined in young men despite calls for increased bone health research in men (NIH, 2007). Given these limitations, it is important to investigate variables that may influence these relationships, such as dietary restraint.
Dietary restraint (DR) refers to the use of cognitive, rather than physiological, cues to either lose or maintain weight (Herman & Mack, 1975). DR has been positively associated with exercise behavior (McLean & Barr, 2003). Further, males and females classified as high dietary restrainers (HR) consume fewer calories than low dietary restrainers (LR), but report higher BMIs (Klesges, Isbell, & Klesges, 1992). HR also report greater food awareness and healthier diets (Klesges et al., 1992, McLean and Barr, 2003 and Tepper et al., 1996) than LR. However, the relationship between DR and OP beliefs and knowledge has not been investigated. Therefore, the purpose of the present study was to examine differences in health beliefs and knowledge related to OP between HR and LR. Consistent with research on other health variables (e.g., Klesges et al., 1992) it was hypothesized that HR would score higher on all measures.
