Satiety, Microbiome, Appetite Regulation, and Tracking Energy Across Targeted Snacks: Acute Postprandial Study (SMARTEATS-PP)

August 21, 2026 updated by: Zoe Global Limited

The ZOE SMART EATS (Satiety, Microbiome, Appetite Regulation, and Tracking Energy Across Targeted Snacks) Acute Postprandial Study: Investigating the Acute Effects of a High-fibre Plant-based Snack Bar on Subjective Postprandial Hunger, Energy Intake and Eating Behaviour in Healthy UK Adults.

The goal of this clinical trial is to learn how eating different snack foods affects acute hunger, energy intake and eating behaviour in healthy adults. The study will be conducted remotely over 5 days.

The main questions it aims to answer are:

  1. Does eating a snack bar intervention change how hungry participants feel later in the same day?
  2. Does eating a snack bar intervention change participants' energy intake, nutrient intake and eating behaviour on the same day?
  3. Does eating a snack bar intervention change participants mood, energy levels and alertness later in the same day?

Researchers will compare an intervention snack bar to a control snack bar to see if the intervention improves hunger, energy intake, eating behaviour, and other subjective measures.

Participants will:

  • Eat 2 snack bars for breakfast on 2 separate days, with 2 days in between
  • Not eat anything after 9pm the night before each test day
  • Fill out short online surveys (under 5 minutes) before breakfast and at set times over the next 3 hours
  • Not eat for 3 hours after breakfast
  • Write down everything they eat that day

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Diet, and snacking behaviour in particular, plays an important role in long-term health. Snacking now contributes substantially to daily energy intake in the UK and US: data from the ZOE PREDICT study show that 95% of adults snack at least once a day, with snacks accounting for around a quarter of daily energy intake (2.28 snacks/day). However, the average UK snack has a poor nutrient profile, high in refined carbohydrates, added sugars, and saturated fat, and low in fibre and micronutrients, a pattern linked to poorer cardiometabolic health. Despite public health guidance to consume at least 30g of fibre a day, UK adults consume an average of around 20g/day. However, the composition and timing of a snack are important determinants of its effects on hunger, energy, and other health markers.

This trial evaluates an intervention (2 x snack bars) against a control (2 x snack bars that reflect the average nutrient profile of snacks currently sold in the UK). Using a control snack bar means any effects observed can be attributed to the specific formulation of the intervention snack bar, rather than simply to a change in snacking habits or a reduction in overall snack consumption.

The primary aim of the study is to determine whether the intervention snack bars reduce subjective postprandial hunger (in the hours after eating them), compared with control snack bars broadly representative of the average UK snack nutrient profile. The study will be conducted in 2 phases. In this phase (phase 1; acute postprandial study), 54 participants will complete a crossover postprandial study measuring hunger, satiety, mood, energy, and alertness over 3 hours, and as an end of day measure following consumption of the intervention or control; as well as eating behaviour and subsequent energy and nutrient intake on that day. The postprandial design allows the acute, within-day effects of the intervention snack bars to be assessed under tightly controlled conditions.

Study Type

Interventional

Enrollment (Estimated)

54

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Willing and able to follow the study protocol
  • Willing and able to provide informed consent
  • Regular consumption of snacks (≥2 per day)
  • Fibre intake <20 g/d
  • Living in the UK

Exclusion Criteria:

  • Have BMI of less than 18.5 kg/m² or more than 40 kg/m²
  • Have an allergy or intolerance to ingredients in the intervention or control snack bars (including inulin) or cannot eat the food products safely and comfortably for any reason
  • Have a personal medical history of inflammatory bowel disease, coeliac disease, Crohn's disease, irritable bowel syndrome, chronic constipation, or chronic diarrhoea
  • Have started a new supplement in the past month, or are unwilling to maintain current supplement use throughout the study
  • Previously purchased any ZOE products (including Daily30, ZOE gut health bar or ZOE app membership).
  • Have taken any medication or product that may modify the measured study outcomes, in the past 3 months (including but not limited to: fibre supplements, antibiotics, non-topical steroids or other immunosuppressive medicines, probiotics or prebiotics, metformin, GLP-1 receptor agonists, lipid-lowering medications such as fibrates, statins, PCSK9 inhibitors, non-steroidal anti-inflammatory drugs)
  • Have used opiate pain medication or a proton pump inhibitor for 8 or more consecutive days during the past 3 months
  • Have experienced a heart attack, stroke or major surgery in the last 2 months
  • Have received treatment for cancer in the last 3 months
  • Are currently pregnant, breastfeeding or planning a pregnancy
  • Are diagnosed with an eating disorder, type 1 diabetes mellitus or type 2 diabetes mellitus

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Intervention
Breakfast test meal consisting of 2 x intervention snack bars
Other: High-fibre plant-based snack bar
A high-fibre plant-based snack bar.
Placebo Comparator: Control
Breakfast test meal consisting of 2 x control snack bars
Other: Control snack bars
Commercially available snack bars (UK); reflects the energy and macronutrient profile of a typical UK snack.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postprandial hunger
Time Frame: Within 3 hours post-test meal consumption.
Assessed using digital visual analogue scales (VAS; 0-100) with anchor points 0 = 'not at all hungry', 100 = 'extremely hungry'. Completed at pre-specified time points immediately before and during a 3h post-meal fast.
Within 3 hours post-test meal consumption.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postprandial satiety
Time Frame: Within 3 hours post-test meal consumption.
Subjective postprandial satiety ratings, assessed using digital visual analogue scales (VAS; 0-100), with anchor points 0 = 'not at all', 100 = 'extremely'. Completed at pre-specified time points immediately before and during a 3h post-meal fast.
Within 3 hours post-test meal consumption.
Postprandial mood and energy
Time Frame: Within 3 hours post-test meal consumption.
Subjective postprandial ratings of mood and energy, assessed using digital visual analogue scales (VAS; 0-100), with anchor points 0 = 'not at all', 100 = 'extremely'. Completed at pre-specified time points immediately before and during a 3h post-meal fast.
Within 3 hours post-test meal consumption.
Eating rate
Time Frame: Duration of test meal consumption (day 1, day 4).
Self-reported eating rate (g/min) of the intervention and control test meals. Derived from the amount of food consumed (g) and self-reported eating duration (mins)
Duration of test meal consumption (day 1, day 4).
Time to next meal
Time Frame: Anticipated 3-6 hours post-test meal consumption (day 1, day 4).
Self-reported time to next meal (mins) following the test meals.
Anticipated 3-6 hours post-test meal consumption (day 1, day 4).
Energy and nutrient intake
Time Frame: Post-3 hour fast to midnight (day 1, day 4).
Energy (kcal) and nutrient intake (g; %EI) following the test meals. Assessed using digital food log (myFood24).
Post-3 hour fast to midnight (day 1, day 4).

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Zoe Global Limited

Investigators

  • Principal Investigator: Berry E Sarah, Professor, King's College London

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 14, 2026

Primary Completion (Estimated)

September 16, 2026

Study Completion (Estimated)

October 1, 2026

Study Registration Dates

First Submitted

August 13, 2026

First Submitted That Met QC Criteria

August 19, 2026

First Posted (Actual)

August 20, 2026

Study Record Updates

Last Update Posted (Actual)

August 24, 2026

Last Update Submitted That Met QC Criteria

August 21, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • ZOE SMART EATS - Postprandial

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

To protect participant privacy, individual participant clinical data and any data that could be used to identify individuals will not be publicly available and cannot be deposited in public repositories. In line with journal requirements, data underlying the results in the publication may be made available to bona fide researchers for reproducibility of results. Proposals, researchers or institutions requesting data will be approved if they meet the standard criteria related to ethics, privacy and data protection regulations.

IPD Sharing Time Frame

Starting 6 months after publication.

IPD Sharing Access Criteria

The study data can be released to bona fide researchers by submitting a research proposal approved by a subpanel of our scientific advisory board which meets once per month with independent members to assess proposals. The data may be pseudo-anonymised or otherwise redacted to comply with the UK General Data Protection Regulation (GDPR). Researchers will be required to enter into a GDPR data sharing agreement before data may be released. Access request proposals should be sent to data.papers@joinzoe.com.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • ANALYTIC_CODE

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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