Thinking Through Food is Medicine Interventions

In this issue of JGIM, Houghtaling et al. provide a thoughtful narrative review of issues around implementing Food is Medicine (FIM) interventions.¹ Their review is both a carefully considered summary of the current literature, and a useful guide to those considering implementing an FIM intervention. Using the Exploration, Preparation, Implementation, and Sustainment Framework, and focusing on the important inner context domain, Houghtaling et al. provide a theory- and evidence-informed implementation checklist.¹ In this accompanying editorial, I hope to contextualize their review by providing a simple way to think through what FIM interventions are trying to achieve.

What Is “Food is Medicine”

FIM interventions provide nutrition resources to manage or prevent specific clinical conditions in a way that is integrated with the healthcare sector.² The central premise of FIM is that individuals experience barriers to healthy eating, and overcoming those barriers will improve health by improving diet quality.^2–4

FIM is a subset of “population health nutrition”—the totality of ways that food and nutrition affect population health.² It is important to remember that much of the most important work in population health nutrition lies outside the realm of FIM. By way of analogy, one can think of exercise and physical activity, which, like food and nutrition, broadly promote good health. Within the overall sphere of exercise and physical activity, there are some interventions best coordinated with healthcare (e.g., structured physical therapy after total knee arthroplasty, or cardiac rehabilitation), but many others which are health promoting but do not need healthcare involvement (e.g., public recreation facilities, greenspaces with walking trails, or protected bicycle paths). Similarly, FIM interventions are only one way to promote health by addressing food and nutrition.

Barriers to Healthy Eating

Overcoming barriers to healthy eating is central to the efficacy of FIM interventions, and there are at least four such barriers to consider. The first is lack of consumption power—the capability to consume healthy food. Sufficient consumption power for healthy food underlies the concepts of food security and nutrition security.⁵

Lack of this consumption power chiefly stems from insufficient purchasing power. At first glance, other reasons may seem salient as well—perhaps few nearby stores sell healthy food, or maybe there are transportation or mobility barriers that make acquiring healthy food difficult. I would argue, however, that these issues often boil down to lack of purchasing power. For instance, a person with sufficient financial resources could have healthy food delivered to them, regardless of local food environment, transportation, or mobility barriers.

A second barrier to healthy eating relates to knowledge and beliefs, such as an individual’s understanding of what healthy food is, for their particular situation.⁴ A third barrier relates to culinary skill, which is a person’s ability to select, store, and prepare healthy food.⁴ A fourth barrier relates to motivation—the desire to consume healthy food. Motivation has many interrelating influences, including stress and mental health, food preferences, one’s current food environment, upbringing, one’s household and peers, and culture.²

Food is Medicine Approaches

FIM interventions are defined by their provision of nutrition resources—resources that grant consumption power for healthy food. A key point of variation for FIM interventions is what resources are provided. Broadly, the provided resources can be “cash-like” or “in-kind.”² Cash-like resources provide cash, a subsidy, or voucher that an individual uses to purchase healthy food from retailers under a budget constraint. Nutrition incentive programs and produce prescription vouchers are examples of cash-like interventions. In-kind interventions provide food directly, such as unprepared grocery items or prepared meals. Examples of in-kind interventions include food pantry interventions or medically tailored meals.

Cash-like interventions can vary in how “prescriptive” they are—for example, some may provide cash, while others may use vouchers to restrict what can be purchased. They also vary in whether they allow purchases of prepared foods. Cash-like interventions require adequate retail options for participants to redeem benefits, which can bring up issues of transportation and access. Costs for cash-like interventions typically include the value of the benefit itself, along with expenses related to enrollment and retention of participants, and administering the benefit, including systems to implement any restrictions placed on what can be purchased.

In-kind interventions vary in the array of foods provided, whether foods are prepared or unprepared, and whether the foods are picked up by the beneficiary or delivered. Costs of in-kind interventions typically include food acquisition, storage, and possibly preparation costs, administrative costs related to enrollment and retention, and, possibly, delivery costs.

In general, compared with in-kind approaches, cash-like approaches typically offer more choice to participants, and are often logistically simpler for an organization to implement (e.g., they typically do not require food procurement, storage, or preparation). In-kind approaches typically require less effort from participants, and may offer greater potential to overcome healthy eating barriers related to knowledge and motivation. They can also, in general, be more tightly tied to dietary recommendations for specific clinical conditions. For a given amount of nutrition resources provided, cash-like interventions will typically cost less than in-kind interventions, owing to economies of scale. An important caveat, however, is that there is extensive variation within cash-like and in-kind interventions, and so specific instances may deviate from these general patterns.

Matching Approaches and Barriers

Components of FIM interventions can target different barriers to healthy eating. As described above, consumption power barriers can be overcome through in-kind benefits, which increase consumption power directly, or cash-like benefits, which increase consumption power through increasing purchasing power. To address knowledge barriers, didactic education and lifestyle intervention using in-person, telehealth, or asynchronous (recorded) sessions or learning modules are possible. Culinary skill can be enhanced through experiential learning, like “teaching kitchens.”⁶ Motivation barriers may be addressed through motivational interviewing, coaching, groups visits, or peer support.² In addition, motivation barriers might be overcome using behavioral economics tools like choice architecture (e.g., making healthy choices more prominent when selecting foods), gamification, or financial incentives.⁷

Rational FIM intervention design creates interventions that address the barriers the population of interest faces, while optimizing over considerations of feasibility, cost, and existing infrastructure and programs.

Evaluating Food is Medicine Interventions

FIM interventions may improve many different aspects of health. Whereas a blood pressure medication might only improve blood pressure, an FIM intervention might improve blood pressure, lower depressive symptoms, and reduce emergency department visits. When evaluating FIM interventions, it is important to assess impacts broadly, lest the benefits of FIM interventions be undercounted.

FIM is an emerging field, and some interventions will not have their expected impact. When this occurs, it is important to determine whether diet quality improved, as that is a key mechanism of action. If there was no improvement, then investigators should re-assess the barriers to healthy eating the intervention population faced, and the effectiveness of the intervention components at overcoming them. It may be possible to re-configure the intervention to make it more effective. If there was improvement, then the degree of improvement was not sufficient to improve the health outcome. This prompts consideration of whether greater improvement is feasible. If so, then the intervention could be re-configured, as above. If not, then FIM may not be useful in this particular case.

The World Outside of Food is Medicine

FIM interventions are only one of many ways to improve population health through better nutrition. Many, perhaps most, of these ways do not require healthcare system involvement. For instance, knowledge and beliefs can be shaped by public health campaigns around healthy eating, nutrition classes (e.g., SNAP-Ed), and nutritional information regulations (such as labelling requirements). Culinary skills can be built through experiential learning opportunities in schools and community settings. And motivation can be shaped by public health campaigns, choice architecture in retail environments, and “traffic light” food labeling.⁸

Consumption power for healthy food is fundamentally shaped by social policy.⁹ Food system subsidies, taxes, and regulations all affect the availability and affordability of healthy food, and commercial determinants of health shape the food environment and contribute to diet-related conditions. These are all key areas for intervention. Moreover, income support programs like the child tax credit and SNAP (the Supplemental Nutrition Assistance Program) strongly affect consumption power. Fundamentally, although FIM interventions can be important ways to mitigate the health consequences of healthy eating barriers, they do not directly address the causes of those barriers.¹⁰ Thus, FIM interventions should occur in parallel with public policy efforts that aim to provide, for everyone, the conditions needed for health.

Conclusions

Food is Medicine interventions provide nutrition resources to improve clinical outcomes. When designing Food is Medicine interventions to overcome the relevant barriers to healthy eating a specific clinical population is facing, Houghtaling et al. give clear guidance as to how to implement such programs.¹ But although Food is Medicine interventions are important, they should occur in parallel with social policy efforts to address the reasons they are needed in the first place.

Declarations

Disclaimer

The funding organizations had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Conflict of Interest

SAB reports research grants from NIH, North Carolina Department of Health and Human Services, Blue Cross Blue Shield of North Carolina, the American Heart Association, the American Diabetes Association, and Feeding America, personal fees from the Aspen Institute, Rockefeller Foundation, Gretchen Swanson Center for Nutrition, and Kaiser Permanente, and receiving royalties from Johns Hopkins University Press for sales of the book “Equal Care: Health Equity, Social Democracy, and the Egalitarian State,” all outside of the submitted work.

Prior Presentation

None.