Quality Over Processing: Scientists Debunk the Biggest Myth About Junk Food

A study of over 200,000 Americans found that overall nutritional quality matters more for health than the degree of food processing. Harvard scientist Xiaowen Wang noted that factory processing itself is not harmful. Participants were divided into four groups based on diet quality and processing. During follow-up, about half faced diabetes, cardiovascular disease, or death. Risk depended on diet quality, not processing.

A large-scale study covering data from more than 200,000 Americans over several decades showed that overall nutritional quality of the diet, not the degree of food processing, is decisive for health. Xiaowen Wang, a research fellow at the Harvard School of Public Health, notes that factory processing itself is not harmful, although many ultra-processed foods are indeed of low quality. Participants were divided into four groups: healthy and highly processed, healthy and minimally processed, unhealthy and highly processed, and unhealthy and minimally processed. During follow-up, about half faced type 2 diabetes, cardiovascular disease, or death. Analysis showed that risk directly depended on overall diet quality: with a healthy diet, the threat decreased; with an unhealthy diet, it increased. Within each category, risks were nearly identical, confirming that nutritional value matters, not processing. Experts advise focusing on the overall composition of the diet, including whole grains, vegetables, fruits, nuts, legumes, and quality vegetable oils.