High intake of ultra-processed food: effects on appetite, cardiometabolic health and biomarkers of dietary intake

Research problem and specific questionsUltra-processed foods (UPFs) have undergone extensive industrial processing and are proposed to delay satiety signaling, leading to overconsumption and weight gain.

While high consumption of UPF is associated with obesity and non-communicable disease, there is no established causal relationship between the degree of food processing, independent of nutrient profile, and health outcomes.

The overall aim of this project is to study the causal effects of a high UPF diet, compared to a nutrient-matched low UPF diet, on appetite and cardiometabolic health. In addition, biomarkers to assess UPF exposure will be identified.

The specific research questions are:What is the impact of a 6-week high UPF intake, compared to a nutrient-matched low UPF intake, on appetite and markers of cardiometabolic health?Can intake of UPF be accurately assessed through a priori defined candidate food intake biomarkers or biomarker patterns?Data and methodWe will perform a randomized, crossover study, comparing high (>90% of energy) and low (<10% of energy) UPF intake, defined by the NOVA framework.

All foods will be provided to participants. Diets will be matched on content of energy and macronutrients. N=40 participants will be randomized to the order of diets, each lasting 6 weeks.

This design is chosen to maximize compliance and difference in UPF exposure, while maintaining equivalent nutrient intake.

This will enable causal analyses of health effects of UPF, independent of nutrient intake.Societal relevance and utilizationDue to concerns regarding the health impact of UPFs, recommendations to limit UPF intake have been requested.

However, evidence is insufficient to determine if food processing, overall or specific types, per se really is of public health concern.

Unfounded recommendations to limit UPF intake would negatively impact those who rely on UPFs for convenience and low cost.

The results of the proposed study can be used by both food industry and consumers, to inform future industrial development and consumption of UPF.

In addition, the results will inform future dietary recommendations regarding UPF intake.Plan for project realizationRecruitment and intervention will be carried out during 2025-2026.

Outcome assessments will include a wide range of cardiometabolic and appetite markers, measured in blood, urine and feces. In addition, biomarkers of UPF intake will be identified through both a priori and exploratory approaches.