NCT05253547

Brief Summary

The aim of the study is to provide proof of the effectiveness, acceptability, healthfulness and nutritional adequacy of dietary guidelines to reduce greenhouse gas emissions. The study will compare the effect of dietary advice based on 1) healthy climate-friendly dietary guidelines (intervention group) or 2) standard healthy dietary guidelines (control) on greenhouse gas emissions associated with dietary intake over 12 weeks.

Trial Health

90
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
355

participants targeted

Target at P75+ for not_applicable

Timeline
Completed

Started Mar 2022

Geographic Reach
2 countries

3 active sites

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

February 8, 2022

Completed
15 days until next milestone

First Posted

Study publicly available on registry

February 23, 2022

Completed
26 days until next milestone

Study Start

First participant enrolled

March 21, 2022

Completed
1.2 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

June 1, 2023

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

June 1, 2023

Completed
Last Updated

October 4, 2023

Status Verified

October 1, 2023

Enrollment Period

1.2 years

First QC Date

February 8, 2022

Last Update Submit

October 3, 2023

Conditions

Dietary HabitsHealthy DietHealthy NutritionPersonalized Nutrition

Keywords

Sustainable dietsGreenhouse gas emissionsClimate-friendlyPersonalized nutrition

Outcome Measures

Primary Outcomes (1)

  • Diet-related greenhouse gas emissions reported as kilograms of carbon dioxide equivalents per day

    Participants will record their diet at baseline (habitual diet) and endpoint (intervention diet) using an online 24-hour recall method. Diet-related greenhouse gas emissions will be estimated using food, nutrient and food-related greenhouse gas emissions databases (measured as kilograms of carbon dioxide equivalents). The primary outcome measure is the change in diet-related greenhouse gas emissions (kgCO2-eq/day) as a result of the intervention diet.

    12 weeks

Secondary Outcomes (6)

  • Calcium intake (milligrams per day)

    12 weeks

  • Iron intake (milligrams per day)

    12 weeks

  • Urinary iodine (micrograms per liter)

    12 weeks

  • Serum vitamin D status (25(OH)D nanomole per liter)

    12 weeks

  • Serum lipids (milimoles per liter)

    12 weeks

  • +1 more secondary outcomes

Study Arms (2)

Healthy climate-friendly dietary guidelines

EXPERIMENTAL

Personalised healthy dietary recommendations aimed at reducing diet-related greenhouse gas emissions

Behavioral: Healthy climate-friendly dietary guidelines

Healthy eating guidelines

ACTIVE COMPARATOR

Personalised healthy dietary recommendations based on Ireland's Healthy Eating Guidelines

Behavioral: Healthy dietary guidelines

Interventions

Healthy climate-friendly dietary guidelinesBEHAVIORAL

Personalised climate-friendly healthy dietary recommendations

Healthy climate-friendly dietary guidelines
Healthy dietary guidelinesBEHAVIORAL

Personalised healthy dietary recommendations

Healthy eating guidelines

Eligibility Criteria

Age18 Years - 64 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • Provide written informed consent
  • Be a healthy adult between the ages of 18-64 years old
  • Consume a diet associated with moderate-high greenhouse gas emissions
  • Be in good general health

You may not qualify if:

  • Are pregnant, lactating or planning to become pregnant
  • Are following a medically prescribed diet
  • Have a diagnosis of an acute or chronic medical condition that could interfere with the outcomes of the study. Such diagnoses include (but are not limited to) cardiovascular disease, diabetes mellitus, inflammatory bowel disease, cancers (within the last 5 years), etc.
  • Are immunocompromised or have a suspected immunodeficiency
  • Have excessive alcohol intake (\>28 units per week)
  • Have a known food allergy
  • Regularly consume a single high-dose vitamin or mineral supplement
  • Are participating in another research study
  • Are unable to read, write or understand English.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (3)

University College Cork

Cork, Ireland

Location

University College Dublin

Dublin, Dublin 4, Ireland

Location

Queen's University Belfast

Belfast, United Kingdom

Location

Related Publications (3)

  • Davies KP, Gibney ER, Leonard UM, Lindberg L, Woodside JV, Kiely ME, Nugent AP, Arranz E, Conway MC, McCarthy SN, O'Sullivan AM. Sustainable diets reduce diet-related greenhouse gas emissions and improve diet quality: results from the MyPlanetDiet randomized controlled trial. Am J Clin Nutr. 2025 Oct;122(4):962-971. doi: 10.1016/j.ajcnut.2025.05.015. Epub 2025 Aug 26.

    PMID: 41043876DERIVED

  • Leonard UM, Davies KP, Lindberg L, Woodside JV, Nugent AP, O'Sullivan AM, Gibney ER, McCarthy SN, Arranz E, Kiely ME. Impact of sustainable diets on micronutrient intakes and status: outcomes of the MyPlanetDiet randomized controlled trial. Am J Clin Nutr. 2025 Nov;122(5):1275-1288. doi: 10.1016/j.ajcnut.2025.09.009. Epub 2025 Sep 8.

    PMID: 40930463DERIVED

  • Davies KP, Gibney ER, Leonard UM, Lindberg L, Woodside JV, Kiely ME, Nugent AP, Arranz E, Conway MC, McCarthy SN, O'Sullivan AM. Developing and testing personalised nutrition feedback for more sustainable healthy diets: the MyPlanetDiet randomised controlled trial protocol. Eur J Nutr. 2024 Oct;63(7):2681-2696. doi: 10.1007/s00394-024-03457-0. Epub 2024 Jul 6.

    PMID: 38970665DERIVED

MeSH Terms

Conditions

Feeding Behavior

Condition Hierarchy (Ancestors)

Behavior, AnimalBehavior

Study Officials

  • Aifric O'Sullivan, PhD

    University College Dublin

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
SINGLE
Who Masked
PARTICIPANT
Masking Details
Single-blinded parallel study
Purpose
OTHER
Intervention Model
PARALLEL
Model Details: Parallel randomized control trial
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Lecturer/Assistant Professor

Study Record Dates

First Submitted

February 8, 2022

First Posted

February 23, 2022

Study Start

March 21, 2022

Primary Completion

June 1, 2023

Study Completion

June 1, 2023

Last Updated

October 4, 2023

Record last verified: 2023-10

Data Sharing

IPD Sharing
Will not share

At the start of the study each participant will have a study code assigned to them. All of the data from the trials will be stored using these unique study codes. A file will be set up which will be stored in a location separate to the study data. This file will contain a list which will link each participants contact details to the corresponding ID code. All stored information will be encrypted and protected by a password that only the researcher and PI will know.

Locations

IE(2)GB(1)