The Humane and Sustainable Food Lab is on a mission to use rigorous research to find the most cost-effective interventions to end factory farming. I am its principal investigator. We launched in 2023 and are housed at Stanford University’s School of Medicine in California. 

2024 has been an exciting year for HSFL. We’ve expanded our team, successfully completed some of our major initial projects, and embarked on several new projects. In brief: 

• We expanded our team to a total of two PhD students and three part- or full-time research scientists, thanks to generous foundation and donor support. During 2024, we’ve had 2-3 full-time equivalents across all team members. We are now at 3 full-time equivalents and will increase to 3.5 in February 2025.
• We’ve completed four major projects, detailed below, assessing the effectiveness of diverse interventions.
• We started several other projects focusing on plant-based meat alternatives. These projects address major uncertainties about whether meat alternatives will reduce demand for meat as much as people expect.
• We were fortunate to receive substantial grants from Open Philanthropy and the Brooks Institute, and project-specific grants from the Food Systems Research Fund. However, we do need help to meet our upcoming funding needs (see “How you can help us”). 

Year in Review

We completed the following projects:

1.) Effect of a default portion-size reduction on meat consumption and diner satisfaction: Controlled experiments in Stanford University dining halls

In a randomized, controlled experiment conducted at Stanford’s dining halls, PhD student Anaïs Voski and coauthors tested whether reducing the size of spoons used to serve meat reduces meat consumption. Interestingly, reducing the spoon size by 25% at a burrito bar reduced meat consumption by 18%, but reducing the spoon size by a more substantial 50% at a rotating-entrée station did not reduce meat consumption. These findings highlight the importance of empirically evaluating seemingly straightforward interventions, because they don’t always work as planned. 

2.) Documentary films can increase nationwide interest in plant-based food^[1]

In a longitudinal study using causal inference methods, PhD student Anna Thomas and Research Scientist Jessica Hope investigated effects of popular media that encourage plant-based diets from diverse perspectives, including health, environment, and animal welfare. Each 1-standard-deviation increase in Google search interest for the films What the Health (2017), The Game Changers (2018), and You Are What You Eat (2024) increased search interest in plant-based food by 43%, 11%, and 11% respectively in the following week. However, Google search interest for the films did not affect nationwide consumption of meat or of plant-based alternatives.

3.) Meaningfully reducing meat consumption is an unsolved problem: meta-analysis^[2]

In a meta-analysis, Research Scientist Seth Green and lab affiliate Benny Smith analyzed the most rigorously designed randomized controlled trials (RCTs) that aimed to reduce consumption of meat and animal products (MAP). In contrast to previous reviews that included many poorly designed studies, our meta-analysis suggested that no theoretical approach, delivery mechanism, or persuasive message should be considered a well-validated means of reducing MAP consumption. By contrast, reducing consumption of red and processed meat (RPM) appears to be an easier target, but comes at a steep cost to animal welfare given the small-body problem.

4.) Reanalysis of “A longitudinal study of meat reduction over time in the UK”

In a re-analysis of an important longitudinal study on causes of meat and animal product consumption, Research Scientist Jared Winslow used rigorous statistical methods to re-assess the study’s main conclusions. Issues in the original analysis precluded confident interpretation of this otherwise excellent study’s results. He found that some findings held up, but other findings were reversed upon re-analysis: for example, we found that motivation to decrease consumption was associated with subsequent decreased consumption, which one might expect, even though the estimate from the original analysis was in the opposite direction. He also found that consuming plant-based alternatives, and perhaps also handling raw meat, were associated with subsequent changes in meat consumption and related ideation.

We started the following projects:

1.) Traditional and Contemporary Meat Options Study (TACOS)

Research Scientists Jessica Hope, Jacob Peacock, and Seth Green designed, piloted, and preregistered a randomized online experiment to test how the presence and type of plant-based meat alternatives on a restaurant menu affects consumers’ purchases of different meats. Our experiment will the protein options available in a realistic Chipotle menu (fast-casual Mexican). Our primary hypothesis is that the presence of plant-based meats on the menu will decrease the number of orders of animal meat, in a dose-dependent fashion. Participants will be randomized into the three arms, which will differ only in their menu choices. Arm 1 will replicate the February 2024 menu at Chipotle restaurants, including sofritas, their plant-based meat substitute. Arm 2 will remove this option. Arm 3 will retain sofritas, but also add a second plant-based meat designed to mimic chicken (“chick'nitas”). We plan to begin data collection in January 2025. Along with the next project, this project will inform the design of our future intervention studies in real food-service settings.

2.) Analyzing effects of plant-based meat alternatives in restaurants

Using an unprecedented new dataset of fine-grained time series from 30 restaurants that have recently introduced plant-based meat alternatives (PBMA) to their menus, Research Scientists Jared Winslow and Jacob Peacock are testing the extent to which introducing PBMAs reduces meat consumption (vs. just provides additional options to consumers who would already have chosen a plant-based option, a key concern given Jacob’s previous work). They are using causal inference methods to model daily sales data and the effects of PBMA introductions on meat sales, accounting for secular trends, cyclicity, and probable confounders. 

3.) Animal welfare modeling for university food procurement

Stanford's dining services are working to evaluate the planetary health impacts of their food purchasing. As part of these efforts, Research Scientists Jared Winslow and Jacob Peacock are providing an assessment of animal welfare impacts (see “Real-world impact” below). This entails collecting baseline data on food purchasing and projecting those baselines forward under different scenarios. (For example, one scenario might model a change toward the Planetary Health Diet, as proposed by the EAT-Lancet Commission.) They will then model the animal welfare impacts of each scenario via a measure of aggregate animal welfare, similar to disability-adjusted life years. Welfare factors for individual foods purchased will be calculated in direct consultation with producers to evaluate on-farm welfare. The results will provide Stanford's dining services with a direct comparison of the animal welfare and climate impacts of food purchasing scenarios. Furthermore, by providing fine-grained empirical purchasing data, the model will provide a more accurate and meaningful basis for cost-effectiveness calculations of food-service interventions in general. Ultimately, our goal is for this modeling to serve as a precedent for other universities’ climate action plans, and we plan to disseminate our approach to other universities through our existing partnership with Menus of Change University Research Collaborative.

4.) Multi-site study of multi-modal plant-based nudges in dining halls

Simple behavioral nudges show promise in reducing meat consumption. Preliminary studies suggest interventions like making plant-based options the default or increasing plant-based choices can be effective. However, uncertainties remain about designing real-world interventions. Many studies are conducted in artificial settings and assess only one intervention at a time, limiting their feasibility in diverse food-service environments. Moreover, few studies examine if interventions might backfire by increasing meat consumption later. In collaboration with Food for Climate League and Menus of Change University Research Collaborative, we will conduct a controlled experiment at a university dining hall. This will involve making plant-based options the default at one station and using meat-reducing nudges at others. This study will also  serve as a model for a multi-site study deploying these interventions at multiple college dining halls nationwide.

Real-world impact of our research to date

• Based on methodological recommendations in our previous meta-analysis, Vegan Outreach decided to conduct randomized controlled studies on the effectiveness of their pledge campaigns. Pilot versions have been run for the past two years. I have been advising on the design, conduct, and interpretation of these studies.
• Based on our article on the small-body problem, the leadership of Stanford Residential & Dining Enterprises decided to formally model and consider animal welfare impacts when setting food systems plans for the entire university through Stanford's Climate Action Plan. Our lab is leading this modeling exercise (see above). The university’s past efforts to reduce carbon emissions in its food supply have involved increasing chicken and fish consumption, so we are excited about the opportunity to bring animal welfare considerations to the table for the first time.
• Based on Anaïs’ study on portion-size reduction, our lab was invited to serve as the lead site for a multi-site study led by the Food for Climate League, the Menus of Change University Research Collaborative, and Greener By Default. As lead site, we have worked with these organizations to substantially revise the overall multi-site protocol: (1) ensuring that the interventions attempt to reduce all ABF and do not nudge people toward chicken and fish; and (2) making major improvements to scientific rigor (e.g., using individual-level data collection to ensure adequate power and using within-dining-hall comparisons rather than randomizing separate dining halls).

Leadership, teaching, and outreach

• We opened our virtual Humane & Sustainable Food Lab seminar series to the public and hosted 9 speakers this year. These seminars have provided valuable opportunities to start building an academic community around farmed animal welfare and to workshop project ideas.
• Research Scientist Jessica Hope guest-lectured for Stanford course “Rethinking Meat”, emphasizing the small-body problem for this primarily climate-focused audience.
• I am on the Food Systems Working Group for Stanford University's Climate Action Plan, a major university-wide initiative to plan the next decade of climate action for Stanford operations. I advise on animal welfare impacts of food systems changes.
• I am on the research advisory boards of Greener By Default, Climate Refarm, and Sentience Institute, and informally advise Vegan Outreach. I advise on prioritization, research design, statistics, and interpretation of research results.

Next year

In addition to finishing our ongoing projects listed above, we’re excited about establishing strong ties with other food-service partners besides colleges and universities, especially ones that could scale interventions widely. We are in promising conversations with a major corporation about rigorously testing and then implementing a plant-rich meal intervention at their nationwide offices. We are in conversation with another lab at Stanford about building a research partnership, which would help bring other academics into farmed animal welfare as well as open possibilities for yet more ambitious projects. 

How you can help us

You could give us feedback in the comments section or anonymously. 

You could donate to support our research, or introduce us to donors. The combined costs to support our personnel every year, not including material project costs (e.g., payments to participants), has risen to $525,000/year. We are grateful to have received $200,000/year from Open Philanthropy to date, and this by far our largest funding stream. That still leaves $325,000/year that must be raised elsewhere. This funding gap is now too large to fill only via small project-specific grants. If we surpass our funding goals, we will pursue more of our wish-list projects by increasing all of our current staff to full-time effort, then hiring additional staff. 

We might align well with your giving priorities if:

• You highly value farmed animal welfare;
• You are excited about research that could help identify new, tractable, cost-effective interventions; or
• You think building an academic field around farmed animal welfare is valuable.

We might not align with your giving priorities if:

• You are more focused on other cause areas, such as wild animal welfare; or
• You would rather support direct advocacy than research. 

You could connect us to food-service partners, especially restaurants, that might be interested in partnering with us to run experiments (which could range from changing the menu offerings to interventions as simple as offering free samples of plant-based alternatives). 

1. ^{^}

   We will soon write an EA forum post detailing this study; right now we can only provide limited information given academic journal embargoes.

2. ^{^}

   Seth did some of the work prior to his employment with HSFL.