The growing incidence of chronic diseases has, in part, contributed to increased political and societal pressures to ensure public funds are allocated to the provision of services with known effectiveness. In other words, there is a call to action to ensure the programs and services implemented across Canada in population and public health are effective, and that they will result in improved health outcomes for Canadians. There is some evidence to suggest that current practices related to the promotion of healthy dietary behaviours may not adequately address inequities in health, and may even increase disparities. The purpose of this paper is to identify and summarize research findings on the effectiveness of population based interventions on community-based diet and nutrition, which was identified as a priority topic area in the annual report of the Ontario Chief Medical Officer of Health to the legislative assembly.
The health-evidence.ca registry was searched for reviews on diet and nutrition in May 2011. A standardized quality assessment tool was used to assess the methodological quality of each identified review by two independent reviewers. All search results were limited to reviews rated as being of strong methodological quality. Extracted data included age of participants studied in the review, research design, methodological quality rating, details of the interventions evaluated, details describing which outcomes where evaluated as well as how they were measured, and outcome data.
The diet and nutrition search identified 33 high quality reviews, 17 of which reported on outcomes of interest to this review. Outcomes evaluated included: improving diet (N=10), weight change (N=5), and body mass index (BMI) (N=5). Participants studied ranged from healthy adults to obese adults and adults diagnosed with pre-diabetes, as well as children, adolescents, and ethnic and low income populations. The interventions evaluated varied significantly across the reviews but can be classified as follows: improving diet, weight management, fruit and vegetable consumption, nutrition education, sodium reduction, cognitive/behavioural change strategies, lifestyle interventions, self-help interventions, and incentives.