Plant-based Protein-rich Weight Loss Intervention in 55+ Adults With Obesity

NCT07429136 | Recruiting DMC

• 1 other identifier: RAAK.PRO04.033 - RCT
• Study Type: interventional
• Target: 200
• Locations: 1 country
• Sites: 1

Brief Summary

The objective of the 2EAT RCT is to investigate whether a shift towards more plant-based (≥60% with a minimum of 50%) protein intake can be achieved in an energy restricted diet for three and six months in older adults (55+) with obesity. The 2EAT researchers developed a new dietary counseling plan for six months. This includes four individual consultations, five group meetings and three 24h-recalls. In these six months, participants receive dietary counseling focused on energy restriction (-500 kcal), higher protein intake (aim towards 1.2 g/kg/d, minimum of 0.8 g/kg/d). Participants are randomly allocated either to the more plant-based diet (≥60%) or the more animal-based diet (≥60%). At the start of the intervention, participants are provided with a workbook and recipe book. Secondary objectives are to assess the effect after three and six months 2EAT dietary treatment on 1) weight loss and 2) skeletal muscle mass. Exploratory objectives are to assess the effect after three and six months 2EAT dietary treatment on 1) physical health outcomes (muscle mass and physical performance), 2) body composition, 3) metabolic blood parameters, 4) vitality and quality of life, 5) nutritional intake, 6) behavioral changes, 7) evaluate the process of the dietary treatment.

Conditions

Obesity

Keywords

Obesity; Ageing

Outcome Measures

Primary Outcomes (1)

• Feasibility of high plant-based protein intake while simultaneously striving for weight loss and increased protein intake

  Three-day food record (plant protein intake as part of total protein intake; g/day)

  At baseline (week 0), in week 13 (halfway), in week 26 (end), and optional follow-up (week 52)

Secondary Outcomes (4)

• Feasibility of a weight loss diet during a more plant-based, higher protein intake

  At baseline (week 0), in week 13 (halfway), in week 26 (end), and optional follow-up (week 52)

• Feasibility of an increased protein intake during a more plant-based protein, weight loss diet

  At baseline (week 0), in week 13 (halfway), in week 26 (end), and optional follow-up (week 52)

• Effect of 2EAT dietary treatment on weight loss

  At baseline (week 0), in week 13 (halfway), in week 26 (end), and optional follow-up (week 52)

• Effect of 2EAT dietary treatment on skeletal muscle mass

  At baseline (week 0), in week 13 (halfway), in week 26 (end), and optional follow-up (week 52)

Other Outcomes (40)

• Effect of 2EAT dietary treatment on physical performance

  At baseline (week 0), in week 13 (halfway), in week 26 (end), and optional follow-up (week 52)

• Effect of 2EAT dietary treatment on walking distance

  At baseline (week 0), in week 13 (halfway), in week 26 (end), and optional follow-up (week 52)

• Effect of 2EAT dietary treatment on muscle strength

  At baseline (week 0), in week 13 (halfway), in week 26 (end), and optional follow-up (week 52)

Study Arms (2)

More plant-based diet

EXPERIMENTAL

Participants receive dietary counseling for six months focusing on 1) more plant-based protein (≥60%), 2) higher protein intake (aim 1.2 g/kg/d, minimum 0.8 g/kg/d) and 3) energy restriction (-500 kcal).

Behavioral: More plant-based protein intake during weight loss

More animal-based diet

EXPERIMENTAL

Participants receive dietary counseling for six months focusing on 1) more animal-based protein (≥60%), 2) higher protein intake (aim 1.2 g/kg/d, minimum 0.8 g/kg/d) and 3) energy restriction (-500 kcal).

Behavioral: More plant-based protein intake during weight loss

Interventions

More plant-based protein intake during weight loss BEHAVIORAL

Participants receive dietary counseling for six months focusing on 1) energy restriction (-500 kcal), 2) higher protein intake (aim 1.2 g/kg/d, minimum 0.8 g/kg/d) and according to their assigned diet, either 3) more plant-based protein (≥60%) or more animal-based protein (≥60%).

More animal-based diet; More plant-based diet

Eligibility Criteria

• Age: 55 Years+
• Gender Eligibility Details: All
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Aged 55 or older
• Are obese: have a BMI of \>30 kg/m2 or BMI \>27 kg/m2 and waist circumference \>88 cm (women) or \>102 cm (men)
• Living independently (not in a health facility)
• The willingness that the general practitioner will be notified of study participation
• Written informed consent
• Willingness to comply with the protocol
• Consent of the study physician

You may not qualify if:

• Inability to understand the Dutch language
• Cognitive impairment (MMSE \<15)
• Use of total or partial parenteral nutrition (TPN)
• Alcohol or drug abuse in the opinion of the investigator
• Current enrolment in a fixed rehabilitation program or other intervention studies
• Palliative treatment or a life expectancy of ≤ 3 months
• Following a vegetarian or vegan (100% plant-based) diet
• Bariatric surgery
• Active medical treatment interfering with this intervention (e.g. weight loss medication as Ozempic, cancer patients receiving systemic and immune therapy)
• Physical disabled: unable to meet the general daily exercise guideline for adults
• Planned a holiday during the intervention period and is unable to attend group- or individual sessions for \> 3 weeks
• Diagnosed with unstable coronary heart disease (CHD), decompensated heart failure, uncontrolled hypertension or uncontrolled arrhythmias (e.g. heart failure NYHA \>3)
• Diagnosed degenerative neurocognitive disorders
• Diagnosed with renal failure
• COPD GOLD \>3

Sponsors & Collaborators

• Amsterdam University of Applied Sciences: lead

Study Sites (1)

Hogeschool van Amsterdam

Amsterdam, South Holland, 1067SM, Netherlands

RECRUITING

MeSH Terms

Conditions

Obesity

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Peter Weijs

  Amsterdam University of Applied Sciences

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Susanne Wildemast

CONTACT

+31623492734; s.wildemast@hva.nl

Sjors Verlaan

CONTACT

+31657442955; s.verlaan@hva.nl

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Participants are either assigned to the 1) more plant-based diet group, or the 2) more animal-based diet group.

Study Record Dates

• First Submitted: December 8, 2025
• First Posted: February 24, 2026
• Study Start: August 13, 2024
• Primary Completion (Estimated): October 1, 2026
• Study Completion (Estimated): April 1, 2027
• Last Updated: February 24, 2026

Record last verified: 2025-12

Locations

NL (1)