Impact of Protein Content of Milk on Post-Exercise Appetite and Energy Intake

NCT ID: NCT07050017

Last Updated: 2025-10-06

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 16 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-05-29
• Study Completion Date: 2025-09-29

Brief Summary

This study aims to investigate the acute effects of consuming milk beverages with different protein content on subjective appetite and energy intake in healthy adults following endurance exercise. Participants will complete an endurance exercise protocol and then consume one of three beverages: a high-protein milk, a regular-protein milk, or an isoenergetic and isovolumetric carbohydrate control drink. Subjective appetite ratings will be assessed using visual analogue scales (VAS) at multiple time points after beverage consumption. Appetite-related hormonal responses, including insulin and acylated ghrelin, will be measured via blood samples. Energy intake will be assessed through an ad libitum test meal. This study will help determine whether different types of milk consumed post-exercise influence appetite regulation, hormonal response, and subsequent energy intake.

Detailed Description

The primary objective of this randomized, double-blind, crossover clinical trial is to evaluate the acute effects of post-endurance exercise consumption of milk beverages with varying protein content on subjective appetite, circulating appetite-related hormones, and subsequent ad libitum energy intake in healthy, recreationally active adult males. The study will recruit at least 12 healthy male participants aged 18-39 years who have been regularly engaged in endurance-based physical activity (e.g., cycling, running, triathlon, orienteering, team sports) for a minimum of one year, with a training frequency of at least three sessions per week lasting 60-90 minutes each. Participants will complete five laboratory visits under a crossover design with a minimum one-week washout period between intervention conditions. The first two sessions will consist of pre-study visits (screening, anthropometric assessments, VO₂max testing, and familiarization). The remaining three visits will involve the ingestion of one of the following beverages in a randomized order: standard-protein milk (0 g protein), high-protein milk (30 g protein), or an isoenergetic carbohydrate-based control beverage (0 g protein). All beverages will be isocaloric and isovolumetric and provided in opaque bottles to ensure double-blind conditions. On each intervention day, participants will perform a steady-state endurance exercise protocol using a calibrated cycle ergometer, followed immediately by the ingestion of one of the test beverages. Appetite will be assessed subjectively using validated Visual Analogue Scales (VAS) at predefined intervals. Venous blood samples will be collected to analyze concentrations of insulin and acylated ghrelin as objective biomarkers of appetite regulation. One hour after beverage consumption, an ad libitum test meal will be provided to quantify subsequent energy intake. The total caloric intake and macronutrient distribution will be recorded and analyzed. This study is designed to provide insight into the role of post-exercise milk consumption-specifically the influence of protein content-on short-term appetite modulation and energy intake regulation in recreationally trained individuals.

Conditions

Appetite; Energy Intake; Post-exercise; Negative Energy Balance

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: OTHER
• Blinding Strategy: DOUBLE

Study Groups

carbohydrate control drink: isoenergetic and isovolumetric with milk beverages.

Isoenergetic and isovolumetric with milk beverages

Group Type: ACTIVE_COMPARATOR

The study will investigate how different amounts of protein (0 g, 15 g, and 30 g) in post-exercise beverages affect appetite and energy intake following endurance exercise.

Intervention Type: BEHAVIORAL

The study will investigate how different amounts of protein (carbohydrate control drink : 0 g, reguler milk : 15 g, and high-protein milk : 30 g) in post-exercise beverages affect appetite and energy intake following endurance exercise.

regular milk

containing 15 g protein

Group Type: EXPERIMENTAL

The study will investigate how different amounts of protein (0 g, 15 g, and 30 g) in post-exercise beverages affect appetite and energy intake following endurance exercise.

Intervention Type: BEHAVIORAL

The study will investigate how different amounts of protein (carbohydrate control drink : 0 g, reguler milk : 15 g, and high-protein milk : 30 g) in post-exercise beverages affect appetite and energy intake following endurance exercise.

high-protein milk

containing 30 g protein

Group Type: EXPERIMENTAL

The study will investigate how different amounts of protein (0 g, 15 g, and 30 g) in post-exercise beverages affect appetite and energy intake following endurance exercise.

Intervention Type: BEHAVIORAL

The study will investigate how different amounts of protein (carbohydrate control drink : 0 g, reguler milk : 15 g, and high-protein milk : 30 g) in post-exercise beverages affect appetite and energy intake following endurance exercise.

Interventions

The study will investigate how different amounts of protein (0 g, 15 g, and 30 g) in post-exercise beverages affect appetite and energy intake following endurance exercise.

The study will investigate how different amounts of protein (carbohydrate control drink : 0 g, reguler milk : 15 g, and high-protein milk : 30 g) in post-exercise beverages affect appetite and energy intake following endurance exercise.

Intervention Type: BEHAVIORAL

Eligibility Criteria

Inclusion Criteria

• The study will include healthy, physically active male participants aged 18-39 years who have been engaging in recreational endurance sports (such as cycling, running, triathlon, orienteering, or team sports) for at least one year, with a minimum frequency of 3 sessions per week lasting 60-90 minutes.

Exclusion Criteria

• Current smoker
• Chronic or excessive alcohol consumption
• Use of supplements and/or chronic medications that may affect appetite
• Presence of cardiac, hepatic, renal, pulmonary, neurological, hematological, gastrointestinal, diabetic, thyroid, or psychiatric disorders, and/or musculoskeletal conditions that may limit exercise participation
• Allergy or intolerance to any of the foods or beverages to be consumed during the study
• Unstable body weight (e.g., weight loss greater than 1 kg in the past week)
• Currently following a weight-loss diet
• Diagnosed eating disorders or individuals who cognitively restrict food intake (to be assessed using the Three-Factor Eating Questionnaire)

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 39 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: Yes

Sponsors

Hacettepe University

OTHER

Sponsor Role: lead

Responsible Party

Elif Tunçil

Research Assistant

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

muhammed atakan, Associate Professor

Role: STUDY_CHAIR

Hacettepe University

zeynep ergün, PHD student

Role: STUDY_CHAIR

Hacettepe University

süleyman bulut, Associate Professor

Role: STUDY_CHAIR

Hacettepe University

hüsrev turnagöl, professor

Role: STUDY_CHAIR

Hacettepe University

tahir hazır, professor

Role: STUDY_CHAIR

Hacettepe University

yiğitcan karanfil, Assistant professor

Role: STUDY_CHAIR

Hacettepe University

Locations

Hacettepe University

Ankara, , Turkey (Türkiye)

Countries

Turkey (Türkiye)

Other Identifiers

SBF-25-059

Identifier Type: -

Identifier Source: org_study_id