Research program – III:
Sustainable Food Systems

The food systems team, a subset of the funded efforts of the Global KAITEKI Center at ASU, focuses its work at the intersections of health, sustainability, and well-being. This work is meant to bind the spirit of KAITEKI with real-world food systems issues that affect consumers’ health and lives. As such, the team advanced work along its main areas of interest – consumer level food waste, dietary shifts towards plant-based diets, and COVID-19 and its impact on both food waste and health behaviors.

As a result of its efforts, the team has generated a number of publications, scientific reports, and a consumer-facing educational website focused on strategies and tools to assist people in reducing food waste in their homes. Publications include two studies related to the recent pandemic and its effect on a national sample of US adults in terms of both health and sustainability behaviors, and a study in collaboration with the City of Phoenix evaluating an intervention to reduce household food waste. Two other manuscripts will soon be submitted focusing on predictive models of food waste and social support for healthier, more sustainable diets. A total of 8 scientific presentations have been delivered at national and international conferences.

Current and future projects will focus on developing holistic, scalable models of behavior change that foster improved health and sustainability behaviors simultaneously, with a new study on this approach to be underway in early 2022. Further, the team will explore new models of dietary shifts that better balance animal and vegetable calorie intake.  

Research project III.1: Food Waste Reduction

Work on food waste reduction has been comprehensive, including: 1) development and validation of a new tool to measure household food waste and related behavioral constructs; 2) completion of a food waste reduction intervention and follow-up study with dozens of households in Phoenix, Arizona, which showed that a values-based educational intervention was effective in significantly reducing household food waste over 5 weeks; 3) development of a new and powerfully predictive model for food waste behaviors in the US; and 4) development of a new tool to explore social support among individuals adopting or maintaining a plant-based diet.

The food waste reduction intervention was a strong demonstration of the idea that weaving values within a technologically mediated educational intervention could be effective not just in reducing household food waste, but eliciting long-term maintenance of that reduction. Further, this intervention set the stage for exploring multiple different factors within a predictive model that contribute to explaining food waste behaviors. As such, the food systems team conducted an international study on food waste, developing models that incorporate theoretically and empirically based behavior-change constructs that seek to explain food waste behavior. Because we hypothesized that factors such as personal and social norms may be strongly associated with culture, we sought to examine our theoretical model across different populations, starting with four countries (US, Canada, Mexico, Japan).

For our modeling work, we incorporated novel, validated behavior-change scales into an ecological-change behavior model (the Comprehensive Action Determination Model [CADM]) seeking to explain the phenomenon of food waste. We compared and contrasted the original CADM with alternative models that also integrated factors shown in the literature to be of importance in the prevention of food waste, such as emotions, cultural influences, and demographic factors. The CADM showed good model fit for the US and Canada samples – in other words, our statistical analysis revealed that the structure of the model described the data well. Moreover, the model explained an impressively large proportion of the variance in food waste behavior, more than any other model in the current literature. The latter indicates that the factors included in the CADM largely explained changes in perceived food waste among American and Canadian adults. The original CADM further showed inadequate model fit and a smaller variance explained for the Mexico and Japan samples, indicating that the factors included in the model and/or the relationship between the factors vary in these particular populations. An exploration of alternative models revealed that collapsing ‘personal and social norms’ into a single factor and omitting the direct effect of ‘habit’ on food waste improved model fit for the Japan model – this may indicate that our current concept of ‘personal and social norms’ may be inadequate, and ‘habit’ may operate through different pathways in Japanese culture.

Research project III.2: Dietary Shifts and Well-being for a KAITEKI Future

To explore novel areas that might assist individuals in achieving healthier, more sustainable diets, the research team developed new tools that assess important concepts that can be incorporated into future work, specifically the development of a new model that explains the adoption of a plant-based diet. This new social support for plant-based diets scale, based on original items of the Multidimensional Scale of Perceived Social Support, assesses the degree of social support provided by four important social groups: family, friends, significant other, and community. Our statistical analyses revealed that the scale has strong psychometric properties including construct validity (the ability of the scale to measure what it is intended to measure), convergent validity (whether the scale is associated with similar hypothetical constructs such as happiness and satisfaction with life), and discriminant validity (whether the scale differs from opposite hypothetical constructs such as depression and loneliness). Further, the scale can be used as a predictor of adherence to plant-based diets.

The team has taken the next steps in scale development in planning for an intervention focused on dietary shifts. The team developed and is now gathering data on a new ‘animal-based food frequency questionnaire,’ the AFFQ, to be able to quickly and reliably evaluate the extent to which animal-based food choices populate an individual’s daily diet. This scale will be deployed as part of a new intervention in which participants will participate in a program focused on increasing fruit and vegetable consumption while decreasing animal food intake and food waste simultaneously. In doing so, the intervention is meant to elicit health and sustainability outcomes that do not depend on dramatic changes in dietary intake with the hope of achieving persistence in behavior change over time. This intervention is set to be conducted in early 2022.

Research project III.3: Impacts of COVID-19 on Health and Sustainability Behaviors

We designed a unique survey to collect data on the impacts of COVID-19 on household characteristics, food waste and health behaviors in the US. We collected responses from a nationwide sample of 946 household food purchasers. This study was the first published to explore the impacts of COVID-19 on household food waste in the US. Similar studies have been conducted in other countries, which allowed us to perform meaningful comparisons and identify potential cultural/regional differences in food waste changes during crisis situations. The survey results revealed substantial COVID-19-related disruptions in households throughout the US.

The findings of our study indicated that overall, perceived household food waste decreased during the COVID-19 pandemic. However, increased perceived food waste was noted in a subgroup of the study sample. We conducted analyses to identify the factors that predicted increased perceived food waste during the pandemic to elucidate potential opportunities to improve crisis response in the US in the future. The results revealed that food stockpiling was a significant predictor of increased food waste during the pandemic, which has important policy implications indicating the need to improve communication during crisis situations to prevent stockpiling of foods that will not be consumed. Moreover, we found that wasting fresh vegetables and frozen food was associated with greater odds of increased food waste. 

Our second study on COVID-19 focused on health-related behaviors and other factors. This study included analyses of lifestyle and dietary healthfulness changes using 958 survey responses from US primary household food purchasers. Information was collected related to demographics, COVID-19-related household changes, and health-related habits before and during the pandemic. Binary logistic regression identified predictors of perceived increase in dietary healthfulness during the pandemic period. Overall, 59.8%, 16.4%, and 23.4% of participants reported that their eating habits likely changed, may have changed, and likely did not change, respectively. Of the participants whose dietary habits likely or may have changed, 64.1%, 16.8%, and 19% reported healthier, neither healthier nor less healthy, and less healthy eating habits, respectively. COVID-19-related income loss, more meals consumed with household members in front of the television, an increase in food advertisement exposure, increased perceived stress, and better perceived current health were significant predictors of a perceived increase in dietary healthfulness. Overall, dietary habits were perceived to become healthier during the pandemic. The predictors of perceived improvement in dietary healthfulness were surprising and indicate the need for further study of these factors in crisis and noncrisis situations.


  1. ASU Swette Center for Sustainable Food Systems
  2. College of Health Solutions
  3. ASU-Starbucks Center for the Future of People and the Planet

Research personnel

  1. Christopher Wharton, PhD – Associate Professor and PI
  2. Maricarmen Vizcaino, PhD – Research Scholar and co-PI
  3. Kelly Cosgrove, MS – PhD student
  4. Eva Alpine, BS – MS student
  5. Bryanna Leone, BS – MS student
  6. Emily Hinsberger – BS student


  1. Papers in peer-reviewed journals
  2. Cosgrove K, Vizcaino M, Wharton C. COVID-19-related changes in perceived household food waste in the United States: a cross-sectional descriptive study. Int J Env Res & Public Health. 2021;18(3),1104:
  3. Wharton C, Vizcaino M, Berardy A, Opejin A. Waste Watchers: A food waste reduction intervention for Arizona families. Resources, Conservation & Recycling; 164, 2020;164,1-9: .
  4. Cosgrove K, Wharton C. Predictors of COVID-19-related perceived improvements in dietary health: Results from a US cross-sectional study. Nutrients. 2021; 13(6), 2097.


Food waste reduction website: