from participation in group weight-loss programs (particularly if they allow time to process personal problems), or may come from friends or family members. O'Reilly and Thomas (1989) have reviewed social support measures in health behavior research. They synthesized a measure derived from previous research that is specific to risk-reduction efforts. Results show their measure predicts health behavior maintenance. This questionnaire takes about 10–20 minutes to complete.
Sallis et al. (1987) have developed scales for measuring social support for diet and exercise. Two diet support scales (Family Support for Eating Scale and Friend Support for Eating Scale) and two exercise support scales (Family Support for Exercise Scale and Friend Support for Exercise Scale) are available. Subjects rate the frequency with which both family and friends had said or done what was described in the item during the previous three months. Items are rated on a 5-point scale, ranging from "none" to "very often." These scales have good reliability and are correlated with self-reported exercise and diet habits, providing evidence of concurrent criterion-related and construct validity.
In addition to the goal of weight loss itself, programs can be designed to teach patients more about the nature of obesity, nutrition, exercise, health risks, and the pros and cons of dieting. Such knowledge may have beneficial long-term effects on maintenance of weight loss and future attempts to lose weight. An example is the Adult and Child Behavior Knowledge Scales.
Adult and Child Behavior Knowledge Scales These scales measure knowledge of health behaviors related to cardiovascular disease (Vega et al., 1987). They focus on behavioral capability rather than on the link between behavior and disease. The subscales assess knowledge of dietary sodium, dietary fat, and exercise. The Adult Knowledge Scale consists of 18 multiple-choice and true-false items (six in each of the three subscales) and has a reliability alpha coefficient of 0.80. Test-retest reliability for the total score is also acceptable at 0.76. The Child Knowledge Scale consists of nine multiple-choice and true-false items (three in each of the three subscales) and has a reliability alpha coefficient of 0.51. Test-retest reliability for the total score is 0.73. The Health Behavior Knowledge Scales are useful in assessing differences in knowledge levels among adults and children of differing cultural and language groups.