Published: 11/27/2022

By Jamie Hansen, Communications Manager at the Stanford Center for Innovation in Global Health

Dr. Christopher Gardner

CHRISTOPHER D. GARDNER, PhD, is the Rehnborg Farquhar Professor of Medicine at Stanford University, and the Director of Nutrition Studies at the Stanford Prevention Research Center.

He studies how people should eat and drink to optimize their health, as well as the forces and factors that can successfully motivate people to improve their food and beverage behaviors. His work has found that many of the healthiest food choices for people are also better for the planet, with lower carbon emissions and water use.

We spoke with Dr. Gardner about the ways we can adapt our food systems to provide healthier food across a range of demographics — while also helping the planet.

What does the science tell us about which diet(s) are healthiest and most sustainable for our planet?

As reported in the landmark 2019 EAT Lancet report, we can’t fully mitigate the climate crisis without addressing our food systems. The good news here is that there isn’t one approach for human health and a different one for a sustainable planet; the two are aligned. For decades, national dietary recommendations have recommended shifting to a more whole food plant based diet (WFPB). That refers to more vegetables, legumes, fruits, whole grains, and nuts and seeds. The flip side of that is less animal-sourced foods, and meats in particular. U.S. consumption of meat, especially beef, pork, and poultry, is among the highest in the world, with plenty of room for cutting back. 

Emerging data on planetary boundaries indicates that plant-based diets have a much smaller impact on the environment than animal-sourced foods. Those planetary boundaries go beyond greenhouse gasses to include land use, water use, eutrophication from nitrogen and phosphorous run-off, and biodiversity. This doesn’t have to mean everyone going vegan. We published a review in 2019 suggesting that if Americans shifted 25% of their protein intake from animal foods to plant foods, and cut back by 25% on overall protein intake, the resulting diet would be consistent with more optimal health and have a dramatic effect on lowering the impact of current agricultural practices on greenhouse gasses and water use. There is plenty of room for these kinds of reductions.

In classes that I teach on campus, we have found that awareness of the impact of diet on the environment can be a powerful motivator for making dietary changes. I like to refer to this as Stealth Nutrition. This is not meant to imply any deception, but rather, a stealth approach in terms of presenting environmental sustainability as a motivating factor for healthful diet changes. This can be an alternative to focusing directly on more direct health approaches such as “grams of fiber” or “milligrams of antioxidants.”

What role can Stanford and other academic institutions play in increasing the adoption of healthier, more sustainable food choices — and modeling solutions to food and health challenges?

I’m particularly excited about the role Stanford is playing in this space. Think about the opportunity and the importance of shaping the food preferences of thousands of students every year who will go on to influence many others as parents, business owners, and leaders. The numbers scale up quickly to millions and billions of meals over time.

Eight years ago, Stanford University joined with the Culinary Institute of America (CIA) to create the Menus of Change University Research Collaborative (MCURC) that conceives of university dining halls as living laboratories. In this innovative approach, academics from across multiple disciplines at Stanford partner with dining operators and dining hall chefs to conduct behavioral experiments in the dining halls. We then examined the treasure trove of data collected by dining services on food ordering and consumption. 

Under the leadership of Senior Associate Vice Provost Dr. Shirley Everett, all of the culinary teams across campus are guided by the CIA’s Principles of the Menus of Change, founded on the three pillars of: unapologetic deliciousness, environmental sustainability, and human health. The collaborative has expanded to include more than 60 universities across the country, and holds annual conferences. Moving these efforts from the individual or household level to the institutional level allows for large-scale impact in terms of factors such as carbon emissions. Stanford Health Care is also making institutional efforts to address the trifecta of taste, sustainability and health, part of a larger effort called Healthcare without Harm.

These institutions serve a limited population. What role do institutions more broadly have to play, especially in terms of health equity?

Lessons learned at Stanford University Dining, the MCURC collective of universities, Stanford Hospitals, and Healthcare without Harm, can be expanded to institutions across the country. The opportunities to be disruptive and innovative in other institutional settings, such as worksites and K-12 schools, are tremendous.

Whole fruits and vegetables are offered at a pop-up food pantry at Sacramento State. Photo Credit: ASI_PopUp_Pantry_20180910_0034, flickr

Another partner in these efforts is Food Banks. Second Harvest, serving San Mateo and Santa Clara counties with almost 1,000 distribution sites, has undertaken major changes in this regard in the last decade. Historically, food banks have received donations of non-perishable food items, many of which were of low nutritional value (i.e., packaged processed foods high in refined flour and added sugars). This exacerbates health disparities by using the charitable food system to hand out junk food. But Second Harvest has set new policies, shifted its infrastructure, and now is able to store and distribute fresh produce in greater amounts, making up approximately 50% of what is given out at its distribution sites. 

Collectively, these institutional food settings are contributing importantly to shifting consumer demands. This can translate to shifting agricultural supply chains so that the foods we produce are better aligned with human and planetary health.

While food security (access to any food) is understandably a major concern across the globe, there’s a growing crisis of nutrition both in the U.S.and internationally that you’ve been calling attention to. What does nutrition security look like, and who is most affected?

I am currently chair of the American Heart Association’s Nutrition Committee, and am proud to say that the AHA has taken a leadership role in shifting attention from food security to nutrition security. What that refers to is a shift from quantity to quality. 

For decades, the many U.S. safety net programs such as Supplemental Nutrition Assistance Program [SNAP] and the School Lunch Program, have existed to provide food to those who don’t have enough to eat. In principle, all of these programs aspire to provide nutritious foods. In reality, the focus is often more on quantity than quality. The relatively low nutritional quality of those foods helps exacerbate health disparities. Those most affected are those with the greatest needs — often, people of color and those from lower socioeconomic groups, who already are experiencing the greatest health disparities.

This low nutrition, low-cost, convenience-focused type of food is sometimes referred to as a Western Diet, or the Standard American Diet — appropriately referred to as SAD. Unfortunately, a transition to this type of diet is occurring in low-income countries, as well as globally in large countries like China and India, leading to higher rates of non-communicable diseases (NCDs) like cardiovascular disease, diabetes, and cancer. This is often characterized by low amounts, or lack of access to plant-based foods in favor of low-nutrition, processed foods. Diet has been an important causal factor in the rise of NCDs, but a shift to a more whole food plant based diet could be one of the solutions to this global public health challenge.

 Given the state of our food system, how can we achieve nutrition security equitably across different income levels and cultures, in the US as well as countries around the world?

Historically, a whole food plant based diet was typical in many low-income countries. Grains and beans are both nutritious, as well as being relatively easy to store and purchase in bulk. Some of the most flavorful global dishes come from Middle Eastern, Latin American, Indian, Mediterranean, and Asian cultures where small amounts of herbs, spices, nuts, and seeds were used in grain- and bean-based menus to create great taste and healthy nutrition at an affordable price.

A Vietnamese market offers an array of fresh fruits, vegetables, and beans. Photo credit: Stéphan Valentin unsplash.com

We are now seeing some promising changes at the academic, policy, and governmental level that could make this healthier mode of eating accessible to people of all backgrounds and income levels.

Beyond the AHA, the USDA has now shifted its focus more toward nutrition security. The Friedman School of Nutrition Science and Policy at Tufts University is also emphasizing this shift. This was also a priority in the recently held White House Conference on Hunger, Nutrition and Health. This conference set a goal to “End hunger and increase healthy eating and physical activity by 2030, so that fewer Americans experience diet-related diseases like diabetes, obesity, and hypertension.”  

I am optimistic that we are at a turning point regarding this shift from food security to nutrition security. I’m hopeful that the many organizations currently coming together to address this will be able to start to close the gap in health disparities related to diet.

Stanford is really well poised to take advantage of the new Doerr School of Sustainability and build on this momentum that is being created for shifting food behavior in a way that is aligned with reducing health disparities and saving the planet.

Cover photo: Jennifer Schmidt, unsplash.com