Harvard Study Shows Diet Quality Beats Food Processing for Health
A new study of more than 200,000 U.S. adults followed from the 1980s through the 2020s found that overall diet quality was strongly linked to lower risk of heart disease, type 2 diabetes and premature death. These health associations did not vary substantially with the level of food processing, indicating that the nutritional quality of the diet matters more than whether foods are ultra‑processed.
Researchers, led by postdoctoral fellow Xiaowen Wang at Harvard T.H. Chan School of Public Health, used a plant‑based diet index to separate diet quality from processing level. While many ultra‑processed foods are low in nutritional quality and should be limited, processing itself is not inherently harmful. A plant‑based diet rich in whole grains, fruits, vegetables, nuts, legumes and healthy oils is beneficial even when it includes some processed items. The findings will be presented at the NUTRITION 2026 conference in National Harbor, Maryland.
Entities: American Society for Nutrition · Harvard T.H. Chan School of Public Health · NUTRITION 2026 · National Harbor, Maryland · Xiaowen Wang
Claims
What the coverage asserts, and how well corroborated each claim is across sources.
- [● 3 SOURCES] Many ultra‑processed foods tend to be of poor nutritional quality and should generally be limited or avoided. (Researchers)
- [● 2 SOURCES] The findings will be presented at the NUTRITION 2026 conference in National Harbor, Maryland, July 25‑28. (Researchers)
- [● 3 SOURCES] The study examined over 200,000 U.S. adults followed from the 1980s through the 2020s. (Researchers)
- [● 3 SOURCES] Researchers used a plant‑based diet index framework to assess diet quality and processing levels. (Researchers)
- [● 3 SOURCES] A healthy plant‑based diet rich in whole grains, fruits, vegetables, nuts, legumes and plant oils is beneficial even when it includes some processed foods. (Xiaowen Wang)
- [● 3 SOURCES] The associations between diet quality and health outcomes did not differ substantially by food processing level. (Researchers)
- [● 3 SOURCES] Food processing itself is not inherently harmful. (Researchers)
- [● 3 SOURCES] Higher overall diet quality was strongly associated with lower risk of heart disease, type 2 diabetes, and premature death. (Researchers)