by Marion Nestle
May 29 2026

Weekend reading: Industry influenced opinion of the week

I usually do posts about conflicts of interest on Mondays, but wanted to acknowledge the death of Carlo Petrini right away this week.  So here’s the Monday post.

David A Cleveland, Research Professor in the Department of Geography, and Environmental Studies, University of California, Santa Barbara, sent this one:

Skimming through this I found an emphasis on ‘nuance’, obscuring key distinctions, and calls for more research, while giving little attention to the fundamental basics that could be the basis for nutrition + env dietary guidelines, e.g. that same nutrients from animal-source foods have much higher climate and environmental impact than those nutrients from plant foods, or imported and off-season produce has higher impact than local in season.

The study: Conrad, Z. 2026. Should the Dietary Guidelines for Americans include sustainability? A critical perspective. The American Journal of Clinical Nutrition:101309. DOI: https://doi.org/10.1016/j.ajcnut.2026.101309.

Its conclusion: “The federal government, which has responsibility for translating the scientific evidence into publicly accessible dietary guidance, is not currently well-positioned to communicate the nuances of nutrition-sustainability science to the general public.”

Conflict of interest: “ZC has received research awards for diet sustainability projects from the United States Department of Agriculture (Pulse Crop Health Initiative), the Jeffress Trust Awards Program for Research Advancing Health Equity, American Pistachio Growers, the National Dairy Council, and the National Pork Board.”

Comment: The beef industry did not pay for this commentary and neither did the dairy industry, both big contributors to greenhouse gas emissions.  The author reports working on sustainability projects for the dairy and pork industries, and understands the financial connections as posing conflicted interests, which they most certainly do.

The study begins with a useful review of attempts to get sustainability into the dietary guidelines, starting with the groundbreaking 1980 paper by Joan Gussow and Kate Clancy, “Dietary Guidelines for Sustainability” [16].  It covers the valiant attempt by the 2015 Dietary Guidelines Advisory Committee to recommend consideration of sustainability when making recommendations about intake of red meat. (here’s my version of that bizarre saga).  But the author concludes that we just don’t know enough about sustainability to make such recommendations.  I think we do.