Effects of a High-protein Diet and Resistance Training on Fat-mass Loss Maintenance

NCT ID: NCT07113561

Last Updated: 2026-01-30

Basic Information

• Recruitment Status: ACTIVE_NOT_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 60 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-09-16
• Study Completion Date: 2027-12-31

Brief Summary

This clinical trial investigates whether a high-protein diet combined with resistance training is more effective than a standard low-calorie diet for maintaining fat mass loss in individuals with obesity.

A total of 60 adults with obesity (BMI ≥30 kg/m²) will be randomly assigned at baseline to one of two groups:

1. A control group receiving a balanced low-calorie diet.

2. An intervention group receiving a high-protein, low-calorie diet and supervised resistance training.

All participants will follow their assigned low-energy diets for the first 10 weeks, which constitutes the weight loss phase. The subsequent 42 weeks comprise the weight maintenance phase, where participants will follow an energy-balanced diet adapted to their individual needs and continue in their assigned group.

The intervention group will also complete supervised resistance training three times per week during the first 10 weeks, with continued follow-up throughout the maintenance phase.

Assessments will take place at baseline, week 11, 6 months, and 12 months, and include measurements of fat and lean mass, resting metabolic rate, appetite hormones, glucose metabolism, inflammation, gut microbiota and its metabolites, hedonic appetite, eating behavior, and quality of life and physical function. Participants will also provide food intake records, physical activity dat.

The primary aim is to determine whether the combined high-protein diet and resistance training intervention results in greater long-term fat mass loss and muscle mass preservation than the control diet. Secondary aims include effects on appetite regulation, eating behavior, metabolic health, and patient-reported outcomes.

The study is conducted at NTNU and St. Olavs Hospital in Trondheim, Norway, and registered under the acronym PRO-FIT.

Conditions

Obesity (Body Mass Index >30 kg/m2)

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

High-protein diet and resistance training

Intervention group: Participants will undergo a low-calorie high-protein diet for 10 weeks, followed by a maintenance phase up to the 1-year mark. This group will also participate in supervised resistance training sessions.

Group Type: EXPERIMENTAL

High-protein diet and resistance training

Intervention Type: OTHER

Participants will consume a low-energy high-protein diet for 10 weeks, and participate in supervised resistance training sessions. They will continue a maintenance diet up until the 1 year mark, with bi-monthly follow ups on diet and exercise.

Balanced control diet

Control group: Participants will undergo a balanced low-calorie diet for 10 weeks, followed by a maintenance phase up to the 1-year mark. This group will not receive any active exercise intervention.

Group Type: EXPERIMENTAL

Balanced control diet

Intervention Type: OTHER

Participants will consume a balanced low-energy diet for 10 weeks, and continue a balanced maintenance diet with bi-monthly follow ups up until the 1-year mark No active exercise intervention.

Interventions

High-protein diet and resistance training

Participants will consume a low-energy high-protein diet for 10 weeks, and participate in supervised resistance training sessions. They will continue a maintenance diet up until the 1 year mark, with bi-monthly follow ups on diet and exercise.

Intervention Type: OTHER

Balanced control diet

Participants will consume a balanced low-energy diet for 10 weeks, and continue a balanced maintenance diet with bi-monthly follow ups up until the 1-year mark No active exercise intervention.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• BMI equal to or above 30
• Sedentary lifestyle (<150 minutes moderate physical activity per week and no habitual resistance training (< once weekly)
• < 2 kg body weight change in the 3 months prior to study commencement
• high motivation for lifestyle change
• not currently enrolled in any other obesity or behavioral change program

Exclusion Criteria

• Previous or planned bariatric surgery
• Current or planned usage of medications or anti-obesity drugs known to influence energy metabolism or appetite
• Diabetes (type 1 and 2)
• Women in menopause or post-menopausal women
• Existing cancer diagnosis
• Renal disease
• Substance abuse
• Eating disorders
• Allergies, or intolerances to ingredients in meal packs/supplements intended for use in the study
• Mobility/physical constrains or musculoskeletal issues that could impede participation in the resistance training program

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 50 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University of Alabama at Birmingham

OTHER

Sponsor Role: collaborator

University of Leeds, Appetite Control and Energy Balance Research

UNKNOWN

Sponsor Role: collaborator

University of Copenhagen

OTHER

Sponsor Role: collaborator

St.Olavs Hospital, Trondheim University Hospital, Norway

UNKNOWN

Sponsor Role: collaborator

Norwegian University of Science and Technology

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

Norwegian University of Science and Technology

Trondheim, , Norway

Countries

Norway

Other Identifiers

592611

Identifier Type: -

Identifier Source: org_study_id