Ultra-Processed Foods: What Does NOVA Reveal About

What does NOVA mean by ultra-processed food?

The nutrition paper behind the headline is an established commentary: it was published online in 2017 and appeared in a 2018 issue of Public Health Nutrition. Available through an NIH-hosted archive, it describes the NOVA framework rather than reporting a newly completed NIH experiment. [Original NOVA commentary](https://doi.org/10.1017/S1368980017000234).

NOVA distinguishes four categories: unprocessed or minimally processed foods, processed culinary ingredients, processed foods, and ultra-processed products. The last category includes formulations made with extracted food components and ingredients such as flavors or emulsifiers. Soft drinks and many packaged snack products are examples. Classification considers ingredients and manufacturing methods; packaging alone does not establish that a food is ultra-processed. [NOVA definitions](https://doi.org/10.1017/S1368980017000234).

Do controlled trials show that ultra-processed diets affect weight?

A 2019 NIH inpatient trial assigned 20 adults to ultra-processed and unprocessed diets for two weeks each, in random order. Participants could eat as much as they wanted. They consumed approximately 500 additional calories daily during the ultra-processed phase and gained weight, while losing weight during the unprocessed phase. Because researchers controlled the food provided, the experiment offers stronger evidence about the tested diets than an observational association alone. [Hall and colleagues' randomized trial](https://pubmed.ncbi.nlm.nih.gov/31105044/).

A 2025 Nature Medicine trial added nuance. Researchers randomized 55 adults with overweight or obesity to two eight-week diets, both designed around UK healthy-eating guidance; 50 contributed to the primary analysis. Average weight loss was approximately 2% on the minimally processed diet and 1% on the ultra-processed diet. Both diets produced weight loss, showing that nutritional improvements can matter even when a menu contains substantial ultra-processed food. [Dicken and colleagues' trial](https://www.nature.com/articles/s41591-025-03842-0).

These results leave a mechanistic question unresolved. The 2025 diets differed in energy density, meaning calories per gram, which could help explain different intakes. Short feeding trials cannot establish long-term effects on heart attacks or cancer, or isolate a single ingredient as the cause. The findings support examining the overall food pattern alongside the characteristics of individual products. [Trial discussion and limitations](https://www.nature.com/articles/s41591-025-03842-0).

How can people improve their diet without avoiding every processed food?

WHO guidance emphasizes varied diets containing vegetables, fruit, whole grains, pulses, and appropriate protein sources. Frozen and canned produce can contribute, provided it does not contain added sugars or excessive sodium. Practical changes include replacing a sugary drink with water or adding beans and vegetables to a familiar meal. Convenience foods can help people maintain a balanced diet when time, storage, or cooking facilities are limited. [WHO healthy-diet guidance](https://www.who.int/news-room/fact-sheets/detail/healthy-diet).

The practical implication is to consider both processing and nutritional composition when shopping. Compare similar products for sodium, sugars, saturated fat, and fiber, and choose options that help meet nutritional needs. Public health efforts also need to address affordability and availability: WHO identifies food prices and income among the factors shaping dietary choices. Advice works best when nutritious options are accessible. [WHO dietary principles and food-environment guidance](https://www.who.int/news-room/fact-sheets/detail/healthy-diet).