Health Effects of Ultra-processed Food Intake (UPFront)

Health Effects of Ultra-processed Food Intake: a Randomized Crossover Feeding Study

Ultra-processed food (UPF) intake has been related to negative health effects and incresed energy intake in previous intervention studies. Thus, previous studies have seen weight gain from higher UPF intake which obscures the potentital to see effects on cardiometabolic biomarkers, independent of weight changes. 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 a weight-stable context.

Study Overview

• Status: Not yet recruiting
• Conditions: Microbiota; Cardiometabolic Risk Factors; Diet Interventions
• Intervention / Treatment: Other: Diet high in UPF; Other: Diet low in UPF

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Linnea Bärebring, PhD, Associate professor; Phone Number: +46 0317863771; Email: linnea.barebring@gu.se
• Study Contact Backup: Name: Therese Karlsson, PhD, Associate professor; Email: therese.karlsson@gu.se

Study Locations

• Sweden
  • Gothenburg, Sweden, 40530
    • University of Gothenburg
    • Contact: Linnea Bärebring, PhD, Associate professor; Phone Number: +46 0317863771; Email: linnea.barebring@gu.se
    • Contact: Therese Karlsson, PhD, Associate professor

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age 20-60 years
• Weight stable (less than 5% weight change in the past 3 months)
• No plans to change weight
• Willing to eat the study diet and a mixed diet
• Has provided informed consent to participate in the study

Exclusion Criteria:

• Allergy or intolerance to foods included in the study. Participants with lactose intolerance treated with lactase may participate if they take enzymes.
• BMI <18.5 or >35 kg/m²
• Use of medications known to significantly affect appetite (e.g., oral corticosteroids, antipsychotic medications, or GLP-1 receptor agonists)
• Use of lipid-lowering medications (e.g., statins or PCSK9 inhibitors)
• Diagnosed diabetes or capillary blood glucose at or above 12.2 mmol/L
• Disease associated with malabsorption (e.g., inflammatory bowel disease or celiac disease)
• Previous bariatric surgery
• Established cardiovascular disease (heart failure, myocardial infarction, or stroke) or cancer
• Pregnancy or breastfeeding, or plans to become pregnant or breastfeed during the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Sequence 1: high UPF, low UPF; Diet high in UPF, followed by a diet low in UPF	Other: Diet high in UPF; Diet high in Ultra-processed food (>80 % of total energy intake); Other: Diet low in UPF; Diet low in Ultra-processed food (<20 % of total energy intake)
Experimental: Sequence 2: low UPF, high UPF; Diet low in UPF, followed by a diet high in UPF	Other: Diet high in UPF; Diet high in Ultra-processed food (>80 % of total energy intake); Other: Diet low in UPF; Diet low in Ultra-processed food (<20 % of total energy intake)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Leptin		Change from baseline to 6 weeks
ApoB	Apolipoprotein B	Change from baseline to 6 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Leptin		Change from baseline to 2 weeks
ApoB	Apolipoprotein B	Change from baseline to 2 weeks
Ghrelin, PYY, cholecystokinin, insulin	Other appetite-regulating hormones	Change from baseline to 2 weeks and from baseline to 6 weeks
Blood lipid profile	ApoA1, LDL, HDL, VLDL, total cholesterol, triglycerides, Lp(a)	Change from baseline to 2 weeks and from baseline to 6 weeks
Body weight		Change from baseline to 2 weeks and from baseline to 6 weeks
Body composition	Fat mass and fat-free mass	Change from baseline to 2 weeks and from baseline to 6 weeks
Blood pressure	Diastolic and systolic blood pressure	Change from baseline to 2 weeks and from baseline to 6 weeks
Biomarkers of ultra-processed food intake	Measured in blood and urine	At 2 weeks and at 6 weeks
Gut microbiome	Change in gut microbial composition and diversity (alpha- and beta)	At 2 weeks and 6 weeks
Glucose	Glucose, measured by continuous blood glucose monitoring	Continuous during the first 2 weeks
Energy intake	Ad libitum energy intake at standardized test meal	Change from baseline to 2 weeks and from baseline to 6 weeks
Subjective appetite	Self-rated appetite before and after a standasized test meal	Change from baseline to 2 weeks and from baseline to 6 weeks
Food cravings and eating behavior	Control of Eating Questionnaire, Three Factor Eating Questionnaire, Power of Food Scale	Change from baseline to 2 weeks and from baseline to 6 weeks

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Oral microbiome	Change in oral microbial composition	At 2 weeks and 6 weeks
Compliance	Compliance assessed by food records	At 2 weeks and 6 weeks
Sleep	Pittsburgh Sleep Quality Index	Change from baseline to 2 weeks and from baseline to 6 weeks
Well-being	WHO-5 Wellbeing Index	Change from baseline to 2 weeks and from baseline to 6 weeks

Collaborators and Investigators

• Sponsor: Göteborg University
• Collaborators: Karolinska Institutet; Chalmers University of Technology
• Investigators: Principal Investigator: Linnea Bärebring, PhD, Associate professor, Göteborg University

Study record dates

Study Major Dates

• Study Start (Estimated): August 1, 2026
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: June 3, 2026
• First Submitted That Met QC Criteria: June 3, 2026
• First Posted (Actual): June 8, 2026

Study Record Updates

• Last Update Posted (Actual): June 8, 2026
• Last Update Submitted That Met QC Criteria: June 3, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Ultra-processed food
• Other Study ID Numbers: 2025-08976-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Ethical approvals and legal issues must be considered and resolved before data of individuals can be shared.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No