DO BELIEFS, KNOWLEDGE, AND PERCEIVED NORMS ABOUT DIET AND CANCER PREDICT DIETARY CHANGE

Objectives. We hypothesized that belief in an association between diet and cancer, knowledge of dietary recommendations and food composition , and perceived norms would predict healthful dietary changes. Methods . Data are from a population-based sample of Washington State resident s (n = 607). Psychosocial constructs measured at baseline (1989/90) we re used to predict changes in dietary practices, fat intake, fiber int ake, and weight over 3 years. Results. Adults who strongly believed in a diet-cancer connection decreased the percentage of energy consumed from fat by 1.20 percentage points and increased fiber intake by 0.69 g, compared with decreases of 0.21 percentage points and 0.57 g among those with no belief (P < .05), Adults with knowledge of the National Cancer Institute fat and fiber goals decreased their percentage of ene rgy from fat by 1.70 points compared with an increase of 0.27 points a mong those with little knowledge (P < .05). Food composition knowledge and perceived pressure to sat a healthful diet were not significant p redictors of changes in fat intake, fiber intake, or weight. Conclusio ns. Interventions that increase the public's beliefs in diet and healt h associations and communicate diet recommendations can encourage heal thful dietary change.