SCIENTIFIC EVIDENCE

Where Can I Find Scientific Evidence to Support a Healthy Eating Law or Policy Idea?

introduction

Laws and policies relating to promoting healthy eating and access to healthy food often can spark controversy. These kinds of policies may draw charges of government overreach into personal liberties and rights. Having research or evidence to support the need for the proposed policy change can help counteract these concerns.

Many healthy eating laws and policies are novel and innovative, so the scientific evidence base for this area is in the early stages. For some types of policies (such as school food related policies, or policies in child care centers), more research has been done; for others, the scientific evidence base is emerging. Thus, in addition to scientific evidence, advocates, community members, and policymakers can also build their own evidence through use of surveys, interviews, and lived experience.

The Healthy Food Policy Project has begun to identify and organize publicly available sources that collect or provide reviews of scientific research on laws and policies (including policy ideas) to promote healthy eating and/or access to healthy food. The sources provided here do not focus on specific articles or reports; rather, they are online, publicly accessible databases, listings and compilations of research, and primarily of systematically reviewed research, related to healthy eating policy and nutrition. A systematic review is a methodological search of scientific studies and reports that collects and analyzes relevant research to create a summary of the available evidence.

We understand that this list is not comprehensive, and of course, it does not include other important forms of evidence such as community members’ lived experiences, and practice-based evidence. But we hope it provides a good starting point for those interested in learning more about the healthy food policy scientific evidence base. We plan to continue to grow this resource, so if you know of an online source not listed here that you believe might be helpful, please let us know.

Evidence Base Sources

Source Description and Examples of Food Policies Addressed Notes
McMaster University,
Health Evidencei
A large database of systematic reviews in public health. Topics include:

  • Obesity interventions
  • Menu labeling
  • Food subsidy programs
Use the advanced search feature and select “Policy and Legislation” for the Intervention Strategy.

Includes international resources.

County Health Rankings,
What Works for Healthii
A database of laws and policies focused on healthy eating, active living, tobacco control, and other public health concerns. The site also provides an evidence ranking, the expected benefit, and specific examples of effectiveness for policies. Policy Approach categories relevant to food:

  • Increase access to healthy food options
  • Promote healthy eating
  • Reduce access to unhealthy foods

Examples of policies and programs ranked in this database include:

  • Child-focused advertising restrictions for unhealthy foods & beverages
  • Community gardens
  • Community kitchens for food processing
  • Electronic Benefit Transfer payment at farmers’ markets
Search under the “Diet and Exercise” section.
The Centers for Disease Control and Prevention,
CDC “Winnable Battles” iii
A site describing various public health policy approaches that are considered “winnable.” Topics include:

  • Artificial trans fats
  • Food marketing to kids
  • Breastfeeding
  • Healthy eating in schools
  • Menu labeling
  • Food access (through zoning)
  • Sodium reduction
This FAQ sheetiv is a helpful companion resource.
Cochrane Database of Systematic Reviewsv A site for systematic reviews in health care and health policy. Searchable topics include Public Health, which includes a Food Supply and Access subtopic. Relevant results include:

  • Government efforts to reduce sodium intake
  • Interventions to reduce sugar-sweetened beverage consumption
Includes international resources.
Healthy Eating Research Programvi A site with healthy eating and food access research and publications. Searchable focus areas include:

  • Menu-labeling
  • Beverages
  • Nutrition and agriculture policy
  • Food and beverage marketing
Searchable by resource type, age group, and race and ethnicity.
The Centers for Disease Control and Prevention, The Community Guidevii A site that classifies public health interventions into categories based on the strength of the evidence base. Relevant sections include:

  • “Obesity: School-Based Programs”
  • “Obesity: Worksite Programs”
Sortable by topic area, resource type, and finding type.
Office of Disease Prevention and Health Promotion, Healthy People 2020viii A site with a list of national health goals and relevant data. Resources are ranked by strength of evidence. Examples include:

  • Obesity: Meal and Fruit and Vegetable Snack Interventions to Increase Healthier Foods and Beverages Provided by Schools
  • Strategies to Reduce Sodium Intake in the United States
The site can be searched using a sortable list of criteria including “Topic Areas”, one of which is “Nutrition and Weight Status.”
The Surgeon General’s National Prevention Strategyix A site providing a list of the Surgeon General-recommended laws to promote nutrition. Topics include:

  • Food deserts/food access
  • Breastfeeding
  • Food quality and safety
  • Healthy eating in government facilities/schools
University of York Centre for Reviews and Disseminationx A site of providing systematic reviews of health and social care interventions. The site provides results from several other databases and published articles. Examples of helpful results:

  • Effectiveness of interventions in preschool children
  • Interventions to increase healthy eating in infants
Includes international resources.
USDA Center for Nutrition Policy and Promotion Nutrition Evidence Libraryxi A site with systematic reviews to inform federal nutrition policy and programs. Sample resources:

  • 2015 Dietary Guidelines Advisory Committee Systematic Reviews
  • Nutrition Education Systematic Review Project
Includes international resources.
Accelerating Progress in Obesity Prevention: Solving the Weight of the Nation,xii Institute of Medicine of the National Academies A site that provides a compilation of policies recommended by the National Academy of Medicine. Covers a large number of topics, such as:

  • Breastfeeding
  • School and workplace obesity and health
  • Menu/nutrition labeling
  • Food advertising/marketing
  • Sugary beverages
Click the “Contents” icon in the top left corner to access different chapters and/or search the whole book for different key terms. Helpful information on this resource is located here.xiii
Strategies to Reduce Sodium Intake in the United States,xiv The Institute of Medicine (now National Academy of Medicine) A report that provides recommendations for reducing sodium intake. Examples from Chapter 9:xv

  • Change sodium-specific nutrition labeling standards
  • Reduce sodium in food
  • Campaign to reduce sodium consumption
Click the “Contents” icon in the top left corner to access different chapters and/or search by different key terms.
World Health Organization Global Database on the Implementation of Nutrition Actionxvi An interactive site for sharing standardized information on nutrition mechanisms, policies, and actions. Topics include:

  • Nutrition Action Themes for the United States
Includes international resources.

Additional Resources

These resources are not currently as substantial or relevant to policy as those listed above. However, they may grow to include more evidence base information in the future.

University of Prince Edward Island, Evidence Based Practice: Foods and Nutritional Sciencesxvii
A compilation of evidence-base databases regarding food and nutritional sciences, with an emphasis on clinical dietetics practices. Some databases from this resource may be included in above table. Areas broadly include:

  • Diet, nutrition and obesity
  • Health policy
  • Public health interventions

Campbell Collaboration Library of Systematic Reviewsxviii
An international database with systematic reviews, evidence-based summaries and policy briefs on a variety of topics in a variety of settings, one of which is nutrition. Topics include:

  • Food interventions
  • Food supplementation