Marino · Nutrients 2021 · systematic review · n=99 studies (1,378,454 participants)

A Systematic Review of Worldwide Consumption of Ultra-Processed Foods: Findings and Criticisms.

Cited 326 times in the scientific literature.

Level 3 - non-randomized controlled study

Systematic review of non-randomized observational dietary studies

PubMed 34444936 · doi:10.3390/nu13082778 · record verified 2026-08-28

What was done

Authors conducted a systematic review searching PubMed and SCOPUS through March 2021 to examine worldwide consumption of ultra-processed food (UPF) defined by NOVA classification. They included 99 studies with a total of 1,378,454 participants that reported UPF consumption as a percentage of total energy intake. Most studies were conducted in Brazil (n = 38) and the United States (n = 15), with 24-hour recalls being the most frequent assessment tool (n = 63).

What was found

The United States and the United Kingdom showed the highest percent energy intake from UPF, generally exceeding 50%. Italy reported the lowest intake at approximately 10%, which was inversely associated with adherence to the Mediterranean diet. UPF consumption was generally higher in men, younger individuals, and people with overweight or obesity compared to older cohorts.

Why it matters

It provides a consolidated global estimate of ultra-processed food intake, documenting that multiple high-income countries obtain the majority of dietary energy from UPF.

Limits

Most source studies used standard dietary questionnaires not specifically validated to assess NOVA food processing categories. The underlying evidence base is heavily concentrated in a small number of countries (primarily Brazil and the US), and specific effect sizes or confidence intervals are not reported in the abstract.

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