Mediterranean Diet Uptake and Nutrition on Child Health, Inflammation, and Early-life Symbiosis (MUNCHIES) Study

Official title

Mediterranean Diet Uptake and Nutrition on Child Health, Inflammation, and Early-life Symbiosis (MUNCHIES): A Randomized Controlled Trial

Overview

Toddlerhood (ages 2-3) is a critical window when the gut microbiome is still developing and eating habits are being established. Yet, many Canadian toddlers eat diets high in sugar and salt, which may affect long-term health. This study will test whether a MED diet can improve dietary inflammation, gut health, and body composition in toddlers and whether a tailored nutrition education program for parents can help families maintain healthy eating patterns. In this study, toddlers will be randomly assigned to a 3-week MED diet or their usual diet. Families in the MED diet group will receive free meal boxes for the 3 weeks, plus guidance from a nutrition researcher through a structured education program. The standard diet group will continue their regular diet with general nutrition advice. Researchers will collect dietary information, body composition assessments, and stool samples to measure gut microbiome composition and metabolites. This first study of a controlled diet intervention in toddlers, combining behavioral support, high-quality food provision, and advanced gut microbiome analysis, will help understand how early diet shapes lifelong eating habits and health, guiding public health strategies and precision nutrition approaches to prevent chronic disease from early life.

Detailed description

The gut microbiome, central to immune and metabolic regulation, is highly responsive to dietary inputs. In adults, interventions like the Mediterranean (MED) diet rapidly increase beneficial microbial taxa and anti-inflammatory metabolites. Toddlerhood (24-36 months) represents a critical window when the gut microbiome continues to stabilize and dietary patterns become established. Yet, the diets of Canadian toddlers remain suboptimal, often dominated by high-sodium, high-sugar foods.

The aims of this study are to determine the effects of a (i) MED diet food-provision intervention on dietary inflammation, the gut microbiome and metabolites, and body composition of toddlers aged 2-3 years at 3 weeks and (ii) comprehensive, tailored nutrition education program, with or without food provision, in promoting adherence to the prescribed diets at 3 weeks and 3 months post-baseline.

This parallel randomized controlled trial at the University of New Brunswick will randomized parent-toddler dyads to either a 3-week MED diet or a Standard diet. Families in the MED diet group will receive free food provision and a tailored, theory-driven parental nutrition program. They will be provided with packaged food boxes including three meals (breakfast/lunch/dinner) and two snacks for each day of the week. Meals will be developed and prepared by a registered dietitian in UNB's metabolic kitchen under sterile conditions and delivered to parents in coolers. Families in the Standard diet group will continue to consume their regular diet and receive general nutrition education. Both groups will be initially screened using the KIDMED 2.0 to ensure they do not already adopt a MED diet. The nutrition education programs will be delivered over a 3-month period from baseline.

The primary outcome is the between-group difference in Children's Dietary Inflammatory Index scores at 3 weeks, diet adherence, and program satisfaction. Secondary outcomes include microbial diversity, taxa, metabolite profiles, body composition, blood pressure, and additional feeding metrics. Assessments will occur at baseline, 3 weeks, and 3 months. Stool samples will be analyzed using shallow shotgun metagenomics and metabolomics to assess microbial taxa, SCFAs, and other metabolites. Statistical analyses, conducted in R, will include t-tests, PERMANOVA, and mediation models.

The toddler years are a pivotal time for shaping lifelong eating habits and health outcomes, persisting into adolescence and adulthood. This is the first trial to test a controlled dietary intervention in toddlers, integrating behavioural theory and patient-oriented research. It will bring together a multifaceted team, combining expertise in nutrition and dietetics with cutting-edge knowledge in genomics for gut microbiome analysis. Findings will inform public health strategies and advance precision nutrition to reduce chronic disease risk from early life.

Interventions

• Behavioral Mediterranean Diet Nutrition Program
  A nine session nutrition and feeding program designed to assess how a Mediterranean-style diet influences toddler gut health, body composition, and inflammation. Toddlers will receive Mediterranean-style foods for the first three weeks, followed by continued guidance through bi-weekly educational sessions focused on meal preparation, food variety, and adherence. Specifically sessions will cover key topics such as toddler nutrient needs, budget-friendly meal planning, picky eating, family mealtim
• Behavioral Standard Diet Education Program
  A nine session general toddler nutrition education program designed to reflect typical dietary patterns in Canadian families. Families receive sessions on topics such as feeding styles, cultural foods and feeding practices, understanding nutrition labels, food safety, choking hazards and prevention, healthy recipes, myths and misinformation, and meal structure and routines. No study foods are provided. Toddlers maintain their usual diets throughout the study while completing the same measurement

Primary outcome measures

• Mediterranean Diet Adherence [Time frame: Baseline, at 3 weeks, and at 3 months after enrollment.]
• Program Feasibility and Acceptability [Time frame: Ongoing throughout study (baseline to 3 months).]
• Children's Dietary Inflammatory Index (C-DII) [Time frame: Baseline, at 3 weeks, and at 3 months after enrollment.]

Secondary outcome measures (3)

• Gut Microbiome Diversity, Composition, and Metabolites [Time frame: Baseline, at 3 weeks, and at 3 months after enrollment.]
• Toddler Anthropometrics, Body Composition, and Blood Pressure [Time frame: Baseline, at 3 weeks, and at 3 months after enrollment.]
• Nutrition-Related Behaviors and Feeding Practices [Time frame: Baseline, at 3 weeks, and at 3 months after enrollment.]

Eligibility criteria

Inclusion criteria

• Parent is ≥19 years of age.
• Carried a singleton pregnancy.
• Delivered at term (≥37 weeks gestation).
• Delivered vaginally or by cesarean section.
• Infant was born with a birth weight between 2,500 g and 4,500 g.
• Toddler is between 24 and 36 months of age at enrollment.
• Parent is able to communicate in English.
• Parent is willing to adhere to the Mediterranean diet for their toddler for 3 weeks.
• Parent is willing to participate in a nutrition education program for 3 months.
• Parent is willing to complete all measurements and provide a stool sample from their toddler.

Exclusion criteria

• Toddler has food allergies or dietary restrictions (e.g., gluten-free) that make it difficult to follow a Mediterranean diet.
• Toddler is at high risk for food allergies (e.g., strong family history of multiple food allergies common to the Mediterranean diet).
• Toddler is already following a Mediterranean diet.
• Toddler has had recent or active consumption of antibiotics, probiotics, or prebiotic drops.
• Toddler has an active acute illness, such as fever, diarrhea, or constipation.
• Toddler was born with a congenital illness or malformation that could affect diet, inflammation, gut health, or body composition.
• Toddler is currently breastfeeding, formula-feeding, or combination feeding.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Prevention

Study locations

Canada · 1 center

• University of New Brunswick — Fredericton

Publications

• Kheirmandparizi M, Gouin JP, Bouchaud CC, Kebbe M, Bergeron C, Madani Civi R, Rhodes RE, Farnesi BC, Bouguila N, Conklin AI, Lear SA, Cohen TR. Perceptions of self-monitoring dietary intake according to a plate-based approach: A qualitative study. PLoS One. 2023 Nov 28;18(11):e0294652. doi: 10.1371/journal.pone.0294652. eCollection 2023. PMID 38015899
• Kebbe M, Leung K, Perrett B, Reimer RA, Adamo K, Redman LM. Effects of Infant Formula Supplemented With Prebiotics on the Gut Microbiome, Gut Environment, Growth Parameters, and Safety and Tolerance: A Systematic Review and Meta-Analysis. Nutr Rev. 2025 Mar 1;83(3):422-447. doi: 10.1093/nutrit/nuae184. PMID 39832301
• Redman LM, Phelan S, Apolzan JW, Beyl RA, Altazan AD, Dickey MS, Simeon E, Flanagan EW, Cabre HE, Sparks JR, Kebbe M, Caughey AB, Valent AM, Hsia DS, Yin E, Keadle SK. Protocol for a randomised controlled trial of a weight maintenance intervention to promote fat loss in pregnant individuals with obesity. BMJ Open. 2025 Feb 25;15(2):e095804. doi: 10.1136/bmjopen-2024-095804. PMID 40000086
• Kebbe M, Eaton A, Dyson M, Scott S, McHUGH T, Yaskina M, Ladha T, Islam B, Talwar K, Wincott J, Ball G. Testing the Feasibility, User Experiences, and Preliminary Effect of Conversation Cards for Adolescents(c) For Behavior Change and Collaborative Goal Setting in Primary Care: A Pilot Randomized Controlled Trial. J Health Commun. 2024 Oct 2;29(10):663-671. doi: 10.1080/10810730.2024.2411318. Epub PMID 39374045
• Song X, Yang K, Cheng C, Hu Q, Zhao F, Lu S, Long J, Yang H, Chen S. Higher dietary inflammatory index linked to increased risk of hypertension: a systematic review and dose-response meta-analysis. Eur J Clin Nutr. 2025 Jun;79(6):512-519. doi: 10.1038/s41430-024-01530-9. Epub 2024 Oct 24. PMID 39448814
• Chen GQ, Peng CL, Lian Y, Wang BW, Chen PY, Wang GP. Association Between Dietary Inflammatory Index and Mental Health: A Systematic Review and Dose-Response Meta-Analysis. Front Nutr. 2021 May 5;8:662357. doi: 10.3389/fnut.2021.662357. eCollection 2021. PMID 34026809
• Liu FH, Liu C, Gong TT, Gao S, Sun H, Jiang YT, Zhang JY, Zhang M, Gao C, Li XY, Zhao YH, Wu QJ. Dietary Inflammatory Index and Health Outcomes: An Umbrella Review of Systematic Review and Meta-Analyses of Observational Studies. Front Nutr. 2021 May 19;8:647122. doi: 10.3389/fnut.2021.647122. eCollection 2021. PMID 34095187
• Mayr HL, Thomas CJ, Tierney AC, Kucianski T, George ES, Ruiz-Canela M, Hebert JR, Shivappa N, Itsiopoulos C. Randomization to 6-month Mediterranean diet compared with a low-fat diet leads to improvement in Dietary Inflammatory Index scores in patients with coronary heart disease: the AUSMED Heart Trial. Nutr Res. 2018 Jul;55:94-107. doi: 10.1016/j.nutres.2018.04.006. Epub 2018 Apr 14. PMID 29754829

Identifiers

NCT: NCT07309536 · REB 2025-146

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗