Ketogenic Dietary Intervention in Men With Mild-to-Moderate COPD

NCT07664111 | Completed

• 2 other identifiers: AICU-COPD-KETO-RCT-2026SABF.25.003
• Study Type: interventional
• Target: 34
• Locations: 1 country
• Sites: 1

Brief Summary

Chronic obstructive pulmonary disease (COPD) is associated with persistent airflow limitation, systemic inflammation, reduced exercise capacity, and unfavorable changes in body composition. Nutritional interventions may represent a complementary strategy to improve clinical outcomes in individuals with COPD. This pilot randomized controlled trial evaluates the feasibility, safety, and preliminary effectiveness of an 8-week ketogenic dietary intervention in men with mild-to-moderate COPD. Participants are randomly assigned to either a supervised ketogenic diet or a control group receiving standard dietary advice. The ketogenic diet restricts carbohydrate intake and promotes nutritional ketosis, which is monitored using blood beta-hydroxybutyrate measurements. The primary outcome is change in the FEV1/FVC ratio. Secondary outcomes include systemic inflammation assessed by C-reactive protein (CRP), phase angle measured by bioelectrical impedance analysis, functional exercise capacity assessed by the 6-minute walk test, estimated aerobic capacity, body composition, and selected biochemical safety markers. The study aims to provide preliminary evidence regarding whether a ketogenic dietary approach may improve inflammatory status, functional capacity, and physiological outcomes in individuals with COPD.

Conditions

Chronic Obstructive Pulmonary Disease (COPD)

Keywords

COPD; Ketogenic Diet; Nutritional Ketosis; Pulmonary Function; Body Composition

Outcome Measures

Primary Outcomes (1)

• FEV1/FVC Ratio

  Baseline and Week 8

  Change in the ratio of forced expiratory volume in one second (FEV1) to forced vital capacity (FVC), assessed by spirometry after 8 weeks of intervention.

Secondary Outcomes (6)

• C-Reactive Protein (CRP)

  Baseline and Week 8

• Phase Angle

  Baseline and Week 8

• 6-Minute Walk Distance

  Baseline and Week 8

• Body Mass Index

  Baseline and Week 8

• Fat Mass

  Baseline and Week 8

Study Arms (2)

Ketogenic Diet

EXPERIMENTAL

Participants received an individualized ketogenic dietary intervention for 8 weeks. The dietary prescription provided approximately 60-70% of total energy from fat, 15-20% from protein, and 5-10% from carbohydrates, with carbohydrate intake restricted to less than 50 g/day. Nutritional ketosis was monitored using blood beta-hydroxybutyrate measurements.

Behavioral: Ketogenic diet

Standard Dietary Advice

ACTIVE COMPARATOR

Participants received standard dietary recommendations for chronic obstructive pulmonary disease and were instructed to maintain their habitual dietary patterns throughout the 8-week study period.

Behavioral: Standard Dietary Advice

Interventions

Ketogenic diet BEHAVIORAL

Participants received an individualized ketogenic dietary intervention for 8 weeks. The dietary prescription provided approximately 60-70% of total energy from fat, 15-20% from protein, and 5-10% from carbohydrates, with carbohydrate intake restricted to less than 50 g/day. Nutritional ketosis was monitored using blood beta-hydroxybutyrate measurements throughout the intervention period.

Ketogenic Diet

Standard Dietary Advice BEHAVIORAL

Participants received standard dietary recommendations for chronic obstructive pulmonary disease and were instructed to maintain their habitual dietary patterns during the 8-week study period.

Standard Dietary Advice

Eligibility Criteria

• Age: 40 Years - 75 Years
• Sex: male
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Male sex
• Age between 40 and 75 years
• Clinically stable chronic obstructive pulmonary disease (COPD)
• GOLD stage I or II COPD
• No acute COPD exacerbation within the previous 3 months
• Stable pharmacological treatment for at least 4 weeks before enrollment
• Ability to complete study assessments and comply with dietary instructions
• Provision of written informed consent

You may not qualify if:

• GOLD stage III or IV COPD
• Uncontrolled cardiovascular disease
• Chronic kidney disease
• Severe hepatic dysfunction
• Active malignancy
• Insulin-dependent diabetes mellitus
• Participation in another dietary intervention program within the previous 3 months
• Inability to complete study assessments
• Contraindications to dietary carbohydrate restriction
• Refusal or inability to provide informed consent

Sponsors & Collaborators

• Agri Ibrahim Cecen University: lead

Study Sites (1)

Ağrı İbrahim Çeçen University

Ağrı, Turkey (Türkiye)

Location

Related Publications (5)

• Ji J, Fotros D, Sohouli MH, Velu P, Fatahi S, Liu Y. The effect of a ketogenic diet on inflammation-related markers: a systematic review and meta-analysis of randomized controlled trials. Nutr Rev. 2025 Jan 1;83(1):40-58. doi: 10.1093/nutrit/nuad175.

  PMID: 38219223 RESULT

• Norwitz NG, Winwood R, Stubbs BJ, D'Agostino DP, Barnes PJ. Case Report: Ketogenic Diet Is Associated With Improvements in Chronic Obstructive Pulmonary Disease. Front Med (Lausanne). 2021 Jul 29;8:699427. doi: 10.3389/fmed.2021.699427. eCollection 2021.

  PMID: 34395478 RESULT

• Maddocks M, Kon SS, Jones SE, Canavan JL, Nolan CM, Higginson IJ, Gao W, Polkey MI, Man WD. Bioelectrical impedance phase angle relates to function, disease severity and prognosis in stable chronic obstructive pulmonary disease. Clin Nutr. 2015 Dec;34(6):1245-50. doi: 10.1016/j.clnu.2014.12.020. Epub 2015 Jan 7.

  PMID: 25597016 RESULT

• Collins PF, Yang IA, Chang YC, Vaughan A. Nutritional support in chronic obstructive pulmonary disease (COPD): an evidence update. J Thorac Dis. 2019 Oct;11(Suppl 17):S2230-S2237. doi: 10.21037/jtd.2019.10.41.

  PMID: 31737350 RESULT

• Adeloye D, Song P, Zhu Y, Campbell H, Sheikh A, Rudan I; NIHR RESPIRE Global Respiratory Health Unit. Global, regional, and national prevalence of, and risk factors for, chronic obstructive pulmonary disease (COPD) in 2019: a systematic review and modelling analysis. Lancet Respir Med. 2022 May;10(5):447-458. doi: 10.1016/S2213-2600(21)00511-7. Epub 2022 Mar 10.

  PMID: 35279265 RESULT

MeSH Terms

Conditions

Pulmonary Disease, Chronic Obstructive

Interventions

Diet, Ketogenic

Condition Hierarchy (Ancestors)

Lung Diseases, Obstructive; Lung Diseases; Respiratory Tract Diseases; Chronic Disease; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Diet, Carbohydrate-Restricted; Diet Therapy; Nutrition Therapy; Therapeutics; Diet; Nutritional Physiological Phenomena; Diet, Food, and Nutrition; Physiological Phenomena

Study Officials

• Dursun Alper YILMAZ

  Ağrı İbrahim Çeçen Üniversitesi

  STUDY CHAIR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: Blinding was not feasible because of the nature of the dietary intervention.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: Participants were randomized in a 1:1 ratio to either a supervised ketogenic dietary intervention or a control group receiving standard dietary advice. Outcomes were assessed at baseline and after 8 weeks.

Study Record Dates

• First Submitted: June 15, 2026
• First Posted: June 23, 2026
• Study Start: August 15, 2025
• Primary Completion: March 15, 2026
• Study Completion: June 15, 2026
• Last Updated: June 23, 2026

Record last verified: 2026-06

Locations

TU (1)