A new analysis in Science Advances tracked 42,947 U.S. adults from NHANES and 125,372 adults in the UK Biobank and scored how closely their meals matched the Planetary Health Diet (PHD)—a pattern that emphasizes plant foods and limits red meat and dairy. People in the highest adherence group had a 23% lower risk of death from any cause in the U.S. data and a 16% lower risk in the U.K. data. In the U.K. group, higher adherence was also linked to 16% lower cancer mortality and a 61% lower risk of death from respiratory diseases.  

To test whether these findings hold up beyond two cohorts, the authors pooled results from 37 cohort studies (3.24 million people). Compared with the lowest adherence, the highest adherence to the PHD was associated with 21% lower all‑cause mortality, 17% lower cardiovascular mortality, and 11% lower cancer mortality. Risks were also lower for colorectal cancer (13%), lung cancer (32%), coronary heart disease (17%), stroke (16%), and type 2 diabetes (26%). These pooled results are summarized in Table 2 of the paper.  

Why it matters

The Planetary Health Diet is designed to be good for people and the planet. In this study, the team also estimated the climate footprint of participants’ diets and found that red meat and dairy were the largest contributors to diet‑related greenhouse gas emissions in both datasets—information illustrated in Figure 1 (page 3). That helps explain why shifting toward a PHD‑style plate may bring environmental co‑benefits alongside health gains.  

The more you follow it, the more you may benefit

The researchers used a 0–140 point score (higher means closer to the PHD) and saw a generally linear “more‑is‑better” relationship with lower mortality in both cohorts and in dose‑response analyses.    

What’s in the Planetary Health Diet?

In broad strokes: plenty of vegetables, fruits, whole grains, legumes, and nuts; mostly unsaturated fats; and small amounts of animal‑source foods, especially limited red meat and dairy. (These categories also align with the foods driving the largest emissions in Figure 1.)  

What this means for you

If you’re looking for a single eating pattern that supports long‑term health and sustainability, this analysis adds weight to the Planetary Health Diet. Practical first steps include swapping some red‑meat meals for beans or lentils, choosing whole grains more often, and building half your plate from plants.  

Caveats

This research is observational, so it can’t prove causation. Still, the associations were consistent after adjusting for age, sex, body size, smoking, education, income, and more, and they held up in multiple sensitivity analyses.    

Source: Wang Y. et al., “Planetary Health Diet and risk of mortality and chronic diseases: Results from US NHANES, UK Biobank, and a meta‑analysis,” Science Advances (published Sept. 5, 2025).  

Visual notes: The bar charts in Figure 1 (page 3) show the biggest emission sources in the diet (red meat and dairy), and Table 2 (page 5) lists the pooled risk reductions across 37 studies; Figure 4 (page 6) illustrates the dose‑response curve between higher PHD scores and lower risks.  

Editor’s note: This article is for information only and is not a substitute for professional medical advice.