Nutrition knowledge, outcome expectations, self-efficacy, and eating behaviors by calcium intake level in Korean female college students

BACKGROUND/OBJECTIVES Calcium is important but deficient in diets of young adult women. This study aimed to examine if cognitive factors and eating behaviors differ according to calcium intake based on the Social Cognitive Theory. SUBJECTS/METHODS Subjects were female college students in Seoul, Korea. Three hundred students completed the questionnaire regarding calcium intake, nutrition knowledge, outcome expectations, self-efficacy and eating behaviors. Data on 240 students were analyzed using t-test or χ(2)-test. Subjects were categorized into two groups, high calcium intake (HC, ≥ 650 mg/day) and low calcium intake (LC, < 650 mg/day), according to recommended intakes of calcium for women aged 19-29 years. RESULTS The LC group constituted 77.9% of total subjects. Nutrition knowledge was not different according to calcium intake. Three out of 12 outcome expectations items were significantly different between the HC and LC groups. Subjects in the HC group agreed more strongly with the practical benefits of consuming calcium-rich foods, including 'taste' (P < 0.01) and 'going well with other snacks' (P < 0.05), compared to those in the LC group. Negative expectations of 'indigestion' were stronger in the LC group than HC group (P < 0.001). Among self-efficacy items, perceived ability of 'eating dairy foods for snacks' (P < 0.001), 'eating dairy foods every day' (P < 0.01), and 'eating calcium-rich side dishes at meals' (P < 0.05) differed significantly between the HC and LC groups. Eating behaviors including more frequent consumption of dairy foods, fruits or fruit juice (P < 0.001), anchovy, seaweeds, green vegetables, protein-rich foods (P < 0.05), and less frequent consumption of sweets or soft drinks (P < 0.01) were significantly related to calcium intake. CONCLUSIONS This study found that outcome expectations, self-efficacy in consuming calcium-rich foods, and eating behaviors are important in explaining calcium intake. Nutrition education needs to address practical benefits, reduce negative expectations of calcium-rich foods, increase self-efficacy, and modify eating behaviors contributing to calcium intake.