Plant-based Diet in Older People: What Consequences for Muscle Health?

NCT07681986 | Not Yet Recruiting

• 2 other identifiers: RBHP 2024 BOIRIE 22024-A02027-40
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

This randomized, controlled, two-arm clinical study aims to determine how increasing the proportion of plant-based foods in the diet affects skeletal muscle strength, mass and function, protein metabolism, microbiota and key metabolic markers in healthy older men and women. We hypothesize that diets enriched with animal-based foods will maintain maximal quadriceps strength-the primary outcome of the study-more effectively after the 3-month nutritional intervention than plant-based diets. Proteomic analyses will be performed to identify molecular mechanisms and potential muscle biomarkers reflecting metabolic adaptations of skeletal muscle to plant-enriched diets. In addition, metabolic health markers and micronutrient status will be evaluated to better understand the overall health effects of dietary plant-based transition in older adults.

Conditions

Aging

Keywords

Aging; Older Adults; Plant-Based Diet; Muscle Strength; Skeletal Muscle; Protein Metabolism; Physical Performance; Proteomics; Body Composition; Gut Microbiota

Outcome Measures

Primary Outcomes (1)

• Maximal Quadriceps Strength

  Maximal voluntary contraction of the quadriceps muscle will be measured using a standardized dynamometer. This outcome evaluates the primary effect of the dietary intervention on skeletal muscle strength in older adults.

  Baseline and Month 3

Secondary Outcomes (9)

• Protein metabolism

  Baseline and Month 3

• Short Physical Performance Battery (SPPB) total score

  Baseline and Month 3

• Handgrip strength

  Baseline and Month 3

• Distance covered during the 6-minute walk test

  Baseline and Month 3

• Appendicular lean mass

  Baseline and Month 3

Study Arms (2)

Control diet group

ACTIVE COMPARATOR

Participants follow a standard diet for older adults with approximately 70% of protein from animal sources and 30% from plant sources. Nutritional guidance and follow-up are provided throughout the 3-month study period. Participants maintain their usual eating habits within these proportions, and dietary compliance is monitored through food diaries and regular consultations with the study team.

Other: Control diet

Plant-enriched diet group

EXPERIMENTAL

Participants follow a diet enriched in plant-based foods, with approximately 70% of protein from plant sources and 30% from animal sources, while maintaining adequate total protein intake. Participants receive tailored dietary guidance and support from the study team over 3 months, including meal planning and regular follow-up. Dietary compliance is assessed using food diaries, recalls, and periodic monitoring by the study team.

Other: Plant-enriched dietary intervention

Interventions

Plant-enriched dietary intervention OTHER

Participants follow a diet enriched in plant-based foods with approximately 70% of protein from plant sources and 30% from animal sources for 3 months, with tailored dietary guidance, meal planning support, and compliance monitored through food diaries and periodic follow-up.

Plant-enriched diet group

Control diet OTHER

Participants follow a standard diet with approximately 70% of protein from animal sources and 30% from plant sources for 3 months, with general nutritional guidance and compliance monitored through food diaries and periodic consultations.

Control diet group

Eligibility Criteria

• Age: 65 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Older Adult (65+)

You may qualify if:

• Men and women aged 65 years and older
• Body Mass Index (BMI) between 18.5 and 30 kg/m² (exclusive)
• Physical activity \< 3000 MET-min/week, assessed using the ONAPS-PAQ questionnaire
• Laboratory tests compatible with participation in the study
• Adequate venous status, as assessed by study nurses, allowing catheter placement
• Willingness to participate in study procedures, including indirect calorimetry, functional tests, and assigned dietary intervention (plant-enriched or standard diet)
• Affiliation with the French Social Security system

You may not qualify if:

• Men and women aged 65 years and older
• Body Mass Index (BMI) between 18.5 and 30 kg/m² (exclusive)
• Physical activity \< 3000 MET-min/week, assessed using the ONAPS-PAQ questionnaire
• Laboratory tests compatible with participation in the study
• Adequate venous status, as assessed by study nurses, allowing catheter placement
• Willingness to participate in study procedures, including indirect calorimetry, functional tests, and assigned dietary intervention (plant-enriched or standard diet)
• Affiliation with the French Social Security system
• Patients under legal guardianship, curatorship, deprived of liberty, or under judicial protection
• Claustrophobia

Sponsors & Collaborators

• University Hospital, Clermont-Ferrand: lead
• Centre de Recherche en Nutrition Humaine d'Auvergne: collaborator
• Université d'Auvergne: collaborator
• Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement: collaborator

Study Sites (1)

CHU de Clermont-Ferrand

Clermont-Ferrand, France

Location

Study Officials

• Yves BOIRIE

  University Hospital, Clermont-Ferrand

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Lise LACLAUTRE

CONTACT

+33475754963; promo_interne_drci@chu-clermontferrand.fr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: This is an open-label study. Participants and investigators are aware of the assigned diets due to meal preparation and individualized dietary support. Outcome assessments are conducted without blinding.
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: The primary purpose of this study is to evaluate the effects of a dietary intervention-increasing the proportion of plant-based foods-on skeletal muscle strength and metabolism in older adults. Although no pharmaceutical treatment is used, the intervention aims to improve or maintain physical function and muscle health.

Study Record Dates

• First Submitted: June 18, 2026
• First Posted: July 2, 2026
• Study Start: July 20, 2026
• Primary Completion (Estimated): August 1, 2029
• Study Completion (Estimated): August 1, 2030
• Last Updated: July 2, 2026

Record last verified: 2026-05

Locations

FR (1)