Policies created by public health nutrition experts often face implementation challenges by the general public. Do ineffective policies stem from gaps in understandings between experts/professionals and the public about the real causes of problems and thus the best solutions? Dietary problems (e.g., obesity epidemic and food security) may be better addressed if we apply an understanding of these gaps to target the underlying causes (e.g., time constraints; work-life balance; gender inequality) perceived by the public with solutions that make sense to non-experts. Utilizing freelisting methods and consensus analysis, this research will characterize the understandings of issues related to dietary lifestyle problems, causes, and solutions, and assess how views diverge between experts and laypeople and groups based on gender, age, and country. Closing the gap in understandings about dietary problems will illuminate possibilities for crafting public health nutrition policies that reflect and address the understanding and concerns of the general public and therefore be more effective. Despite decades of dietary advice, US and Japanese health profiles are worsening. Although both are developed nations with high GDP, they have very different dietary lifestyles and health outcomes. Japan has the longest life expectancy in the world, but is following a US health trajectory with dietary changes associated with increases in obesity and lifestyle diseases. In contrast, many Americans aim to emulate Japanese by eating more fish and soy. Experts may perceive poor eating habits as the primary problem, resulting from a lack of nutrition knowledge, and thus propose nutrition education and campaigns. The public, the target of those campaigns, may view the underlying causes as lack of time to prepare healthy food resulting from long working hours and commutes, and costs and availability, particularly in rural Japan where food is primarily sold in convenience stores and in the US food deserts of poor urban neighborhoods. This research moves beyond policy analyses on diet and health in Japan and the US to focus on the understandings and knowledge domains of laypeople, and how their views may differ significantly from the people developing and implementing the policies that are intended to serve them. Consensus analysis has been widely used in public health research to study domains of knowledge about causes and risks for disease, and degree of consensus between different ethnic groups, and between laypeople and physicians. In freelisting, respondents are asked to list all the kinds of X (e.g., dietary problems) they can think of. Since everybody eats, everyone has opinions, ideas and beliefs about problems related to dietary lifestyle. Data can be analyzed by order or frequency, with those items appearing earlier in the list assumed to be more typical of the domain, and high frequency assumed to show consensus. The order and frequency of domain items often differ by variables such as gender, age, and occupation. Methodological innovation derives from the use of a database linking the three domains of problems, causes, and solutions, permitting greater understanding of the gaps and interconnections in knowledge.