What we still don't know about ultra-processed foods with Julia Belluz & Kevin Hall

The American diet has become dominated by ultra-processed foods, but it’s taken a while for scientists to even begin to understand what this really means for our health.One of the researchers at the cutting edge of our nascent understanding is Kevin Hall. A physicist by training, Hall spent 21 years at NIH becoming the country's foremost nutrition scientist before resigning from the agency in 2025.Julia Belluz is an award-winning health journalist and contributing opinion writer at the New York Times who has done some of the best reporting on nutrition and obesity anywhere.Together, they wrote Food Intelligence — an Economist Book of the Year. It's one of the most honest and nuanced books about food and nutrition I've read in a long time, and this conversation reflects that.Highlights:– Kevin's landmark 2019 NIH clinical trial: how it was designed, what it found, and why it was so controversial– Why nutrition science is so underfunded — and how that created a vacuum filled by industry, influencers, and ideology – The MAHA paradox: a movement with the right rhetoric (sometimes) but lacking serious investment in the science to back it up – What the continuous glucose monitor and biohacking craze gets wrong – How food environments (not willpower) drive what we eat, and what changing them would actually require – Kevin's firsthand account of being censored as a government scientist and why he ultimately left NIH after 21 years – What systemic change could actually look like: SNAP reform, marketing restrictions, and making healthy food genuinely competitiveWhere to find Kevin Hall & Julia Belluz:Check out their book Food IntelligenceKevin Hall’s websiteFollow him on InstagramJulia Belluz’s websiteFollow her on InstagramMentioned in this episode:Kevin Hall's 2019 ultra-processed foods clinical trial — Cell MetabolismHow Washington Keeps America Sick and Fat — Helena's 2019 Politico investigation on nutrition research underfundingKevin Hall's departure from NIH — CNNStay in touch:Sign up for Helena’s must-read weekly newsletter: Food Fix.Follow American Dish on Instagram and YouTube.Send ideas and feedback to info@foodfix.coCheck out Forked, the food politics podcast Helena co-hosts with the Food & Environment Reporting Network.Credits: This episode was edited by Adrienne Cruz. Original music by David Bottemiller.