Metabolic Effects of the Exercise-metabolite Lac-Phe

The Metabolic Effects of the Exercise-metabolite N-lactoyl-phenylalanine (Lac-Phe)

The goal of this double-blinded, randomized cross-over clinical trial is to assess the isolated (i.e. outside the context of exercise) effects of Lac-Phe on appetite and glucose concentrations in healthy volunteers with obesity (BMI 28-35).

The main questions it aims to answer are:

• Does Lac-Phe reduce appetite in humans?
• Does Lac-Phe have glucose-lowering properties in humans?

During the study, participants will:

• receive an intravenous infusion of Lac-Phe on one study day and a NaCl infusion on another study day.
• drink a standard mixed meal
• eat an ad libitum meal test
• answer appetite questionnaires
• indirect calorimetry
• blood samples for hormone and substate analyses

Study Overview

• Status: Completed
• Conditions: Healthy Overweight/Obese
• Intervention / Treatment: Other: N-lactoyl-phenylalanine; Other: NaCl

• Study Type: Interventional
• Enrollment (Actual): 23
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • Aarhus N, Denmark, 8200
    • SDCA research laboratory

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• A body mass index (BMI) between 28-35 kg/m2
• Older than 18 years of age
• Hgb within a normal range (females: 7.3-9.5 mmol/L, males: 8.3-10.5 mmol/L)
• Females can be included if they are either postmenopausal or actively use hormonal contraception (e.g., oral contraceptive pill or hormone-releasing intrauterine device).

Exclusion Criteria:

• Medications affecting glucose metabolism (e.g., Saxenda).
• Anemia
• Diabetes
• Ongoing cancer or other acute/chronic serious diseases (PI will determine)
• Inability to understand Danish or English
• Deemed unsuitable to participate by the PI and co-investigators.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Lac-Phe; Intravenous infusion of Lac-Phe	Other: N-lactoyl-phenylalanine; Intravenous infusion of N-lactoyl-phenylalanine (Lac-Phe); Other Names: Lac-Phe
Placebo Comparator: Control; Intravenous infusion of NaCl	Other: NaCl; 0.9% isotonic NaCl infusion

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
ad libitum meal test	Meal intake (kcal) during the ad libitum meal test	On the study day, from times 240 minutes and until meal completion as assessed by study participant

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Lac-phe	plasma concentrations of lac-phe	During the study day, time 0-240 minutes
glucose	plasma concentrations of glucose	During the study day, time 0-240 minutes
lactate	plasma concentrations of lactate	During the study day, time 0-240 minutes
c-peptide	serum concentrations of c-peptide	During the study day, time 0-240 minutes
triglycerider	plasma concentrations of triglycerides	During the study day, time 0-240 minutes
GLP-1	plasma concentration of GLP-1	During the study day, time 0-240 minutes
GIP	plasma concentrations of GIP	During the study day, time 0-240 minutes
Ghrelin	plasma concentration of ghrelin	During the study day, time 0-240 minutes
insulin	serum concentration of insulin	During the study day, time 0-240 minutes
free fatty acids	Serum concentrations of free fatty acids	During the study day, time 0-240 minutes
LEAP2	Plasma concentration of liver-expressed antimicrobial peptide 2 (LEAP2)	From baseline to end of study day (time 0-240 minutes)
Glucagon	Plasma concentration of glucagon	From baseline to end of study day (time 0-240 minutes)
Gastric emptying assessed by acetaminophen	Plasma concentration of acetaminophen following oral acetaminophen intake	From baseline to end of study day (time 0-240 minutes)
Energy expenditure	Indirect calorimetry	After 60 and approx 180 minutes
Subjective appetite - appetite questionaire	We will assess subjective appetite sensations on a visual analog score. Scale range from 1 to 10 centimeters.	Hourly thoughout the study - times 0, 60, 120, 180 and 240 minutes

Collaborators and Investigators

• Sponsor: University of Aarhus

Study record dates

Study Major Dates

• Study Start (Actual): May 13, 2025
• Primary Completion (Actual): March 10, 2026
• Study Completion (Actual): March 10, 2026

Study Registration Dates

• First Submitted: December 16, 2024
• First Submitted That Met QC Criteria: December 16, 2024
• First Posted (Actual): December 19, 2024

Study Record Updates

• Last Update Posted (Actual): March 27, 2026
• Last Update Submitted That Met QC Criteria: March 23, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Appetite; Lac-Phe; Glucose metabolisme
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Overweight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity; N-lactoyl-phenylalanine
• Other Study ID Numbers: 1-10-72-185-23

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: The corresponding author will make data available on reasonable request.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No