Key Words nutrition intervention, chronic disease preventions Abstract Changing dietary behaviors to prevent chronic disease has been an important research focus for the last 25 years. Here we present a review of published articles on the results of research to identify methods to change key dietary habits: fat intake, fiber intake, and consumption of fruits and vegetables. We divided the research reviewed into sections, based on the channel through which the intervention activities were delivered. We conclude that the field is making progress in identifying successful dietary change strategies, but that more can be learned. Particularly, we need to transfer some of the knowledge from the individual-based trials to community-level interventions. Also, more research with rigorous methodology must be done to test current and future intervention options.
INTRODUCTION
Rationale for Changing Dietary Behaviors to Prevent DiseaseDifferences in people's dietary intake are thought to account for more variation in cancer incidence than any other factor, including cigarette smoking (112,123). Most of the supporting scientific evidence comes from observational studies, including aggregate population studies (52,80). Carefully conducted epidemiological observational studies, both prospective and case-control, show repeatedly that dietary factors are associated with several chronic diseases, including coronary heart disease, some types of cancer, stroke, and non-insulin dependent diabetes, and thereby contribute substantially to the burden of preventable illness (31, 36, 41,48,49,54,59,67,79,86,89,94,101,111,118,122). Although there are exceptions (37,51,63,64,93,102,121), these studies are consistent in pointing to the roles of fat, fruits, and vegetables. However, a recent randomized controlled trial of low-fat, high-fiber dietary intervention failed to find benefit in lowering incidence of recurrent adenomas (88
Rationale for the Literature ReviewMany investigators have designed, implemented, and evaluated dietary change interventions targeting these critical nutrients. Although some changes have been made in the general public, the levels of fat, fruit, and vegetable consumption still fall short of goals in the areas of dietary fat intake and daily servings of fruits and vegetables, for example (55). We must identify successful methods of changing dietary behaviors to prevent disease in order to implement them as part of standard public health and primary care medical practice. Several reviews have been published in the past 15 years on the best methods of intervening in dietary behaviors in several areas of public health activity, such as cholesterol-lowering trials (107), worksites (38), patient education (92), cardiovascular disease prevention trials (23, 113), interventions in whole communities (42), and environmental influences (34). However, this disparate literature has not been pulled together. We have conducted this information synthesis to fill in this gap.
Criteria for the Literature SearchWe used an initial e...