Exploring the Use of Genetic and Behavioural Data in Tailoring Dietary and Lifestyle Support

Exploring the Use of Genetic and Behavioural Data in Tailoring Dietary and Lifestyle Support: An n=1 Randomised Trial

Personalised nutrition approaches typically rely on static information such as health status, lifestyle and genetic data. However, adherence often remains low because daily behaviours are influenced by psychological states, motivation and real-time barriers. There is growing interest in whether integrating behavioural signals and timely prompts could strengthen engagement. The purpose of this study is to explore whether incorporating psychological adaptation and just-in-time behavioural prompts leads to better adherence to a personalised nutrition programme compared with commonly used personalised approach (combining health, lifestyle and genetics data without psycho-behavioural adaptation). Using a six-week n-of-1 randomised trial design implemented across multiple participants, the research will also assess the feasibility of delivering this adaptive support in a free-living environment, as well as participants' engagement, acceptability and perceived usefulness. These findings will inform the development of an adaptive personalised nutrition AI agent.

Study Overview

• Status: Active, not recruiting
• Conditions: Adherence to a Personalised Nutrition Programme
• Intervention / Treatment: Behavioral: Neutral message; Behavioral: Psychology-tailored message

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Middlesex
    • Twickenham, Middlesex, United Kingdom, TW1 4SX
      • St Mary's University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Participants must:

  1. Be 18-45 years old.
  2. Have a BMI between 18.5 and 40 kg/m² (normal weight to obesity categories).
  3. Own a smartphone with WhatsApp installed.
  4. Be willing to receive daily messages for 6 weeks.
  5. Be able to provide informed consent.
  6. Be willing to provide a cheek swab for DNA analysis.
  7. Have sufficient English proficiency to understand daily written instructions.

Given that the programme focuses on the six pillars of lifestyle medicine (nutrition, physical activity, sleep, stress management, social connection, and alcohol/substance moderation), participants must be able to safely engage with light lifestyle recommendations.

Exclusion Criteria:

• Participants will be excluded if they:

  1. Have a diagnosed eating disorder or significant disordered eating symptoms.
  2. Are currently pregnant or breastfeeding.
  3. Have any medical condition requiring medically supervised dietary modification (e.g., diabetes requiring medication, kidney disease, coeliac disease).
  4. Are currently taking medication that significantly affects appetite, weight, or metabolism (e.g., GLP-1 agonists).
  5. Work night shifts
  6. Have severe mental health conditions (e.g., moderate-severe depression, psychosis).
  7. Are participating in another behaviour-change or weight-related study.
  8. Are unwilling to receive WhatsApp messages
  9. Are unwilling to receive genetic information This will be checked with PARQ questionnaire

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Static personalisation; All participants receive a fully personalised dietary and lifestyle plan based on: baseline lifestyle and diet; health status; environmental context; genetic polymorphisms (e.g., FTO, APOA2, TCF7L2, CLOCK, TMPRSS6, FADS1/2, MTNR1B, CYP1A2, taste receptors) This ensures that both study arms receive personalised nutrition, reflecting current best practice. Participants receive: One fixed daily behaviour goal, aligned with the weekly pillar; Personalised only according to diet, lifestyle, health status and genetics; Delivered at a pre-selected time chosen by the participant (e.g., 8:30-10:00) No adaptation is made based on: psychological traits; daily mood/energy; anticipated or reported barriers; communication preferences (tone, length, mode) This reflects current "gold standard" personalised nutrition: personalised by biology and lifestyle, but not by psychology or dynamic states.	Behavioral: Neutral message; Participants receive: One fixed daily behaviour goal, aligned with the weekly pillar; Personalised only according to diet, lifestyle, health status and genetics; Delivered at a pre-selected time chosen by the participant (e.g., 8:30-10:00) No adaptation is made based on: psychological traits; daily mood/energy; anticipated or reported barriers; communication preferences (tone, length, mode) This reflects current "gold standard" personalised nutrition: personalised by biology and lifestyle, but not by psychology or dynamic states.
Experimental: Fully personalised; All participants receive a fully personalised dietary and lifestyle plan based on: baseline lifestyle and diet; health status; environmental context; genetic polymorphisms (e.g., FTO, APOA2, TCF7L2, CLOCK, TMPRSS6, FADS1/2, MTNR1B, CYP1A2, taste receptors) This ensures that both study arms receive personalised nutrition, reflecting current best practice. Participants receive the same nutritional and lifestyle content, but daily goals are adapted based on: Stable Traits; Big Five personality; Health locus of control; Optimism bias; Delay discounting; Self-determination; Stress/anxiety baseline; Habit awareness; Values/motivations; Reward preferences Daily State; Morning energy rating (1-5); Expected barriers; Context (home vs office vs weekend) Communication Preferences; tone (coachy, compassionate, factual, brief); message length (low/medium/high); mode (text, voice, image) Environmental and Social Context (e.g., Friday office snacks, partner-driven late dinners)	Behavioral: Psychology-tailored message; Participants receive the same nutritional and lifestyle content, but daily goals are adapted based on: Stable Traits; Big Five personality; Health locus of control; Optimism bias; Delay discounting; Self-determination; Stress/anxiety baseline; Habit awareness; Values/motivations; Reward preferences Daily State; Morning energy rating (1-5); Expected barriers; Context (home vs office vs weekend) Communication Preferences; tone (coachy, compassionate, factual, brief); message length (low/medium/high); mode (text, voice, image) Environmental and Social Context (e.g., Friday office snacks, partner-driven late dinners) Daily personalisation influences: difficulty level of the daily goal; specific behaviour change technique (BCT) chosen (e.g., action planning vs implementation intention vs coping planning); tone, structure and timing of the message; reinforcement style The nutrition content remains identical; only HOW it is delivered changes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Adherence	Adherence is defined as daily completion or active attempt of the assigned lifestyle goal. Adherence is measured using a brief daily self-report item delivered via WhatsApp as part of an ecological momentary assessment. Each day, participants are asked whether they completed or actively attempted the assigned goal (Yes/No). Daily adherence is coded as a binary outcome (1 = completed, 0 = not completed). Adherence rates are calculated as the proportion of completed goal days relative to total analysable person-days and compared between personalised intervention days and static control days. An analysable person-day is defined as a day on which a goal message was successfully delivered and a corresponding adherence response was received within the response window. Days with missing responses or delivery failures are excluded from adherence analyses.	From enrolment to the end of the 6 week intervention

Collaborators and Investigators

• Sponsor: Alexandra King
• Collaborators: Optimyse Nutrition LTD

Study record dates

Study Major Dates

• Study Start (Actual): February 13, 2026
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): June 1, 2026

Study Registration Dates

• First Submitted: January 23, 2026
• First Submitted That Met QC Criteria: February 9, 2026
• First Posted (Actual): February 12, 2026

Study Record Updates

• Last Update Posted (Actual): May 1, 2026
• Last Update Submitted That Met QC Criteria: April 27, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: adherence; behaviour change; personalised nutrition
• Other Study ID Numbers: SMU_ETHICS_2025-26_195

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: The findings will be used to develop a commercial App for dietary behaviour change

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No