A theoretically -based intervention to increase calcium intake in young women
A theoretically-based intervention to increase calcium intake in young women was implemented and analyzed. Although osteoporosis typically occurs in postmenopausal women, it is critical that behaviors designed to protect against osteoporosis (calcium consumption is the most often cited) begin at a young age, before the attainment of peak bone mass. Studies have frequently shown that young women consume too little calcium. Few interventions have targeted calcium intake in young women, however, and the existing interventions have been seriously limited and largely ineffective. The present project addresses limitations of previous trials with an intervention that (a) manipulates health beliefs that are rooted in theories of health behavior and have been previously shown to relate strongly to levels of calcium intake, and (b) permits mediational analyses to explore the mechanism(s) underlying behavioral change. The intervention addressed the inherent difficulty of altering proximal behavior as a preventive strategy for a distal threat by making salient factors associated with calcium intake that may be relevant to young women's lives and by recommending calcium supplements as a simple yet effective alternative to consuming foods high in calcium. A sample of young women (n = 202) were randomly assigned to participate in the calcium intervention or a control program in a study comprised of three parts: (1) an initial session, in which participants viewed the intervention or control program, preceded by assessments of health beliefs, intentions, and behavior, and followed immediately by assessments of health beliefs and intentions; (2) short-term behavioral follow-up, two weeks after the initial session, and (3) long-term behavioral follow-up, two to three months after the initial session. Participants in the intervention condition exhibited greater intentions for dietary calcium consumption and supplement use and greater total calcium intake and supplement use at follow-up assessments. Several psychosocial constructs (perceived severity of osteoporosis, perceived benefits of and perceived barriers to calcium consumption, self-efficacy for consuming calcium and descriptive norms for calcium intake) were found to mediate the relationship between the intervention program and increased intentions and behavior.