Optimal Exercise Frequency to Reduce Liver Fat in Centrally Obese Adults With Non-Alcoholic Fatty Liver Disease

Examining the Optimal Exercise Frequency for Alleviating Liver Fat in Centrally Obese Adults With Non-Alcoholic Fatty Liver Disease (NAFLD): A Comparative Randomized Controlled Trial

This study aims to examine the comparative effectiveness of different exercise frequencies (once-a-week vs. thrice-a-week) for reducing liver fat in centrally obese adults with non-alcoholic fatty liver disease (NAFLD), with weekly exercise volumes aligned with the World Health Organization's physical activity recommendations.

Study Overview

• Status: Active, not recruiting
• Conditions: Obesity; Non-Alcoholic Fatty Liver Disease
• Intervention / Treatment: Behavioral: Once-a-week Exercise; Behavioral: Thrice-a-week Exercise; Other: Usual Care Control

Detailed Description

This study is a three-arm randomized controlled trial. Participants will be randomly allocated to the once-a-week exercise group, thrice-a-week exercise group, or usual care control group. The exercise intervention groups will receive once-a-week or thrice-a-week exercise (with matched weekly exercise volumes). The usual care control group will receive general health education. All interventions will last for 4 months. Outcome measures will be examined at baseline, 4 months (post-intervention), and 10 months (6-month follow-up).

• Study Type: Interventional
• Enrollment (Estimated): 300
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Hong Kong
  • Hong Kong, Hong Kong
    • LKS Faculty of Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 69 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Cantonese, Mandarin, or English speaking Chinese;
2. Aged 18-69;
3. Male or female;
4. Centrally obese according to the Asian-specific cut-off (waist circumference ≥90 cm for males; ≥80 cm for females) and with BMI ≥23;
5. With NAFLD (defined as >5% intrahepatic triglycerides assessed by 1H-MRS);
6. Willing to participate in exercise training to improve NAFLD.

Exclusion Criteria:

1. Regular exercise training (>3 sessions of >60 min of moderate-intensity exercise training weekly) in the past 6 months;
2. Medical history of cardiovascular disease, chronic pulmonary or kidney disease, heart failure, cancer, and/or liver disease except NAFLD;
3. Somatic conditions that limit exercise participation (e.g., limb loss);
4. Impaired mobility due to chronic disease (e.g., chronic arthritis/osteoarthritis, neurological, musculoskeletal, and autoimmune diseases);
5. Daily smoking habit;
6. Excess alcohol consumption (daily ≥20 g of alcohol for men and ≥10 g for women) in the past 1 year;
7. Consumption of certain drugs (e.g., tamoxifen and estrogen) known to be secondary causes of steatosis;
8. Surgery, therapy, or medication for obesity or weight loss in the past 6 months (e.g., gastric bypass, gastric band, sleeve gastrectomy, gastric reduction duodenal switch, or dietitian-prescribed dietary program);
9. Physical changes that considerably affect body composition and weight (e.g., anorexia nervosa, bulimia nervosa, prolonged gastrointestinal and digestive disorders) during the study period.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Once-a-week Exercise; Once-a-week vigorous-intensity exercise for 4 months.	Behavioral: Once-a-week Exercise; Participants in this group will participate in a supervised treadmill exercise program delivered by certified fitness instructors. The prescribed program will involve one session weekly for 4 months, and the duration of vigorous-intensity treadmill exercise per session will be 75 min. Participants will exercise with an exercising heart rate at 6-7 metabolic equivalents (METs). Health information provided to the usual care control group will be made available to the participants in this group.
Experimental: Thrice-a-week Exercise; Thrice-a-week vigorous-intensity exercise for 4 months.	Behavioral: Thrice-a-week Exercise; Participants in this group will participate in a supervised treadmill exercise program delivered by certified fitness instructors. The prescribed program will involve three sessions weekly for 4 months, and the duration of vigorous-intensity treadmill exercise per session will be 25 min. Participants will exercise with an exercising heart rate at 6-7 METs. Health information provided to the usual care control group will be made available to the participants in this group.
Other: Usual Care Control; Bi-weekly health education for 4 months.	Other: Usual Care Control; Participants in this group will receive health education delivered by research personnel. This program will consist of eight two-hour bi-weekly sessions covering major health issues relating to general health and NAFLD, such as non-communicable diseases, infectious diseases, and a healthy lifestyle.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Liver Fat	Intrahepatic triglycerides will be assessed using proton magnetic resonance spectroscopy (1H-MRS) in a 3×3×3 cm voxel.	Baseline and 4 months (post-intervention)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Liver Fat	Intrahepatic triglycerides will be assessed using 1H-MRS in a 3×3×3 cm voxel.	Baseline and 10 months (follow-up)
Change in Abdominal Visceral Fat	Abdominal visceral fat will be assessed using magnetic resonance imaging (MRI).	Baseline, 4 months (post-intervention), and 10 months (follow-up)
Change in Body Fat	Total body fat mass will be assessed using dual-energy x-ray absorptiometry (DXA).	Baseline, 4 months (post-intervention), and 10 months (follow-up)
Change in Body Mass Index	Weight and height will be assessed using a calibrated electronic digital weighing scale and a stadiometer, respectively.	Baseline, 4 months (post-intervention), and 10 months (follow-up)
Change in Waist Circumference	Waist circumference will be assessed using an inelastic measuring tape to the nearest 0.1 cm on bare skin.	Baseline, 4 months (post-intervention), and 10 months (follow-up)
Change in Maximal Oxygen Consumption	Maximal oxygen consumption will be assessed using the modified Bruce protocol.	Baseline, 4 months (post-intervention), and 10 months (follow-up)
Number of Adverse Events	Adverse events related or unrelated to the intervention will be assessed.	Baseline, 4 months (post-intervention), and 10 months (follow-up)
Change in Physical Component Summary Score of the 12-Item Short-Form Health Survey	Physical health-related quality of life will be assessed using the Physical Component Summary scale of the 12-Item Short-Form Health Survey (SF-12). Scores on the scale range from 0 to 100, with higher scores indicating better physical health-related quality of life.	Baseline, 4 months (post-intervention), and 10 months (follow-up)
Change in Mental Component Summary Score of the 12-Item Short-Form Health Survey	Mental health-related quality of life will be assessed using the Mental Component Summary scale of the 12-Item Short-Form Health Survey (SF-12). Scores on the scale range from 0 to 100, with higher scores indicating better mental health-related quality of life.	Baseline, 4 months (post-intervention), and 10 months (follow-up)

Collaborators and Investigators

• Sponsor: The University of Hong Kong
• Investigators: Principal Investigator: Parco M. Siu, PhD, LKS Faculty of Medicine, The University of Hong Kong

Study record dates

Study Major Dates

• Study Start (Actual): March 2, 2023
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: February 13, 2023
• First Submitted That Met QC Criteria: February 13, 2023
• First Posted (Actual): February 23, 2023

Study Record Updates

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

More Information

Terms related to this study

• Keywords: Obesity; Adults; Overweight; Aerobic Exercise; Non-Alcoholic Fatty Liver Disease; Central Obesity; Exercise Frequency
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Digestive System Diseases; Liver Diseases; Fatty Liver; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Overweight; Obesity; Non-alcoholic Fatty Liver Disease; Obesity, Abdominal
• Other Study ID Numbers: HKU-NFF

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The data of individual participants that underlie the results reported in this trial, after de-identification including text, tables, figures, and appendices, as well as study protocol and statistical analysis plan, will be shared after 3 months of study publication. Data will be shared with researchers who provide a methodologically sound proposal for academic purposes. Proposals should be directed to pmsiu@hku.hk to gain access and for data request, a data-access agreement needs to be signed.
• IPD Sharing Time Frame: Beginning 3 months and ending 3 years following the publication of the article.
• IPD Sharing Access Criteria: Data will be shared with researchers who provide a methodologically sound proposal for academic purposes. Proposals should be directed to pmsiu@hku.hk to gain access and for data request, a data-access agreement needs to be signed.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

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