Healthy ParticipantsSMARTEATS-RCTNCT07782593
Satiety, Microbiome, Appetite Regulation, and Tracking Energy Across Targeted Snacks: Chronic Study
A study testing High-fibre plant-based snack bar in people with Healthy Participants and Healthy Adult Subject, run by Zoe Global Limited at 1 site in United Kingdom.
Trial summary
The goal of this clinical trial is to learn how eating different snack foods affects long term hunger and gut health in healthy adults. The study will be conducted remotely over 7 weeks. The main questions it aims to answer are: 1. Read more about this study
- Who is it for?
- Ages 35 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy Participants, Healthy Adult Subject, Healthy Subjects
- What is being tested?
- High-fibre plant-based snack bar
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 100 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 14 Aug 2026to Dec 2026
- Phase
- Interventional
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 35 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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)
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- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United Kingdom1 site, 1 recruiting
- Recruiting
ZOE limited
London
Study Co-ordinator, +44 (0)330 818 8669, smarteats-trial@joinzoe.com
About this study
Official title: The ZOE SMART EATS (Satiety, Microbiome, Appetite Regulation, and Tracking Energy Across Targeted Snacks) Chronic Randomised Controlled Trial: Investigating the Chronic Effects of a High-fibre Plant-based Snack Bar on Subjective Daily Hunger, the Gut Microbiome and Gastrointestinal Symptoms in Healthy UK Adults.
The goal of this clinical trial is to learn how eating different snack foods affects long term hunger and gut health in healthy adults. The study will be conducted remotely over 7 weeks.
The main questions it aims to answer are:
Read more
- Does eating a snack bar intervention for 5-weeks change how hungry participants feel throughout the day compared to a control?
- Does eating a snack bar intervention change gut microbiome, bowel habits, digestive symptoms, and other health measures compared to a control over 5 weeks?
Researchers will compare an intervention snack bar to a control snack bar to see if the intervention improves hunger, gut microbiome, digestive symptoms and other health measures.
Participants will:
- Eat 2 snack bars in place of their usual snacks every day for 4 weeks
- Complete health measurements at the start and end of the study: a health questionnaire, 3-day food diary, 3-day hunger \& satiety survey, body measurements, and a stool sample
- Fill out a short online survey (under 5 minutes) once a week
Read the 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 daily hunger over 5 weeks of daily use, compared with control snack bars representative of the average UK snack nutrient profile. The study will be conducted in 2 phases. In this phase (phase 2; chronic randomised controlled trial), 100 participants (50 per arm) will eat the intervention or control bars daily for 5 weeks. Secondary aims for this phase include the bar's effects on gut microbiome composition, gastrointestinal symptoms, bowel habits (frequency and consistency), subjective mood and energy, sleep quality, and anthropometric measures. The design allows the chronic effects of the intervention snack bars to be assessed when the bars are eaten regularly in place of habitual snack foods.
- Conditions
- Healthy Participants, Healthy Adult Subject, Healthy Subjects, Healthy Adult Volunteer, Healthy Adult Participants
- Being tested
- High-fibre plant-based snack bar, Control snack bars
- Keywords
- Snacks, Snack foods, Dietary intervention, Hunger, Health, Wellbeing, Nutrition study, Microbiome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
High-fibre plant-based snack barOther
High-fibre plant-based snack bars.
Control snack barsOther
Commercially available snack bars (UK); reflects the energy and macronutrient profile of a typical UK snack.
| Study group | Role | What they receive |
|---|---|---|
| Intervention | Experimental | Snack intervention (2x snack bars). To be eaten instead of regular snacks twice a day for 5 weeks. Receives: Other: High-fibre plant-based snack bar |
| Control | Placebo comparator | Control snack (2x snack bars). To be eaten instead of regular snacks twice a day for 5 weeks. Receives: Other: Control snack bars |
What is being measured
The primary outcome is the main question the study is designed to answer.
Daily hunger
Subjective hunger ratings, assessed using digital visual analogue scales (VAS; 0-100), with anchor points 0 = 'not at all hungry', 100 = 'extremely hungry'.
Measured: 2-hourly intervals for 3 days, at baseline and week 5 of the intervention.
Secondary outcomes (11)
Microbiome composition
Relative abundance of selected microbiome species (those included in the ZOE microbiome-health ranks 2025 \& ZOE microbiome-diet ranks 2025), derived from metagenomic analysis of stool samples.
Measured: Baseline, week 5 of the intervention.
Weight
Self-reported body weight (kg).
Measured: Baseline, week 5 of the intervention.
Body mass index (BMI)
BMI (kg/m2) calculated from self-reported body weight (kg) and height (cm).
Measured: Baseline, week 5 of the intervention.
Waist & Hip circumference
Self-reported waist and hip circumference (cm).
Measured: Baseline, week 5 of the intervention.
Gastrointestinal symptoms
Subjective gastrointestinal symptoms, assessed using the Gastrointestinal Symptoms Ratings Scale. Participants rate symptoms on a 7-point scale ranging from 'no discomfort' to 'severe discomfort'.
Measured: Baseline, week 5 of the intervention.
Stool frequency
Self-reported stool frequency (bowel movements per week) assessed via online questionnaire.
Measured: Baseline, week 5 of the intervention.
Stool consistency
Self-reported stool consistency assessed via the Bristol Stool Form Scale. Participants rate their average stool consistency on a 7-point scale.
Measured: Baseline, week 5 of the intervention.
Satiety
Subjective satiety ratings, assessed using digital visual analogue scales (VAS; 0-100), with anchor points 0 = 'not at all', 100 = 'extremely'.
Measured: Baseline (3-days), week 5 of the intervention (3-days)
Subjective energy, mood & alertness
Subjective ratings of energy, mood and alertness, assessed using digital visual analogue scales (VAS; 0-100), with anchor points 0 = 'not at all', 100 = 'extremely'.
Measured: Baseline (3-days), week 5 of the intervention (3-days)
Sleep
Self-reported sleep quality, assessed using the Pittsburgh Sleep Quality Index. Scores range from 0-6, with higher scores indicating poor sleep quality.
Measured: Baseline, week 5 of the intervention.
Energy and nutrient intake
Energy (kcal) and nutrient intake (g/day; %EI), assessed using digital food log (myFood24).
Measured: Baseline (3-days), week 5 of the intervention (3-days).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Aug 2026
- Study start14 Aug 2026
- Primary completion21 Nov 2026 (estimated)
- Study completionDec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (10)Papers the sponsor has linked to this study.
- Other trials for Healthy ParticipantsStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- A parallel design 5-week randomised controlled trial
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Zoe Global Limited
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Berry E Sarah, Professor, Principal investigator, King's College London
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07782593
- Sponsor's protocol ID
- ZOE SMART EATS - Chronic
- Acronym
- SMARTEATS-RCT
- Status last verified
- Sep 2026
- First submitted
- 13 Aug 2026
- Last updated
- 13 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: 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.
Publications
Brown R, Ware L, Gray AR, Chisholm A, Tey SL. Snacking on Almonds Lowers Glycaemia and Energy Intake Compared to a Popular High-Carbohydrate Snack Food: An Acute Randomised Crossover Study. Int J Environ Res Public Health. 2021 Oct 19;18(20):10989. doi: 10.3390/ijerph182010989.
PubMed 34682735Kikuchi H, Yoshiuchi K, Inada S, Ando T, Yamamoto Y. Development of an ecological momentary assessment scale for appetite. Biopsychosoc Med. 2015 Jan 15;9(1):2. doi: 10.1186/s13030-014-0029-6. eCollection 2015.
PubMed 25614760Scheer FA, Morris CJ, Shea SA. The internal circadian clock increases hunger and appetite in the evening independent of food intake and other behaviors. Obesity (Silver Spring). 2013 Mar;21(3):421-3. doi: 10.1002/oby.20351.
PubMed 23456944Beaulieu K, Oustric P, Alkahtani S, Alhussain M, Pedersen H, Quist JS, Faerch K, Finlayson G. Impact of Meal Timing and Chronotype on Food Reward and Appetite Control in Young Adults. Nutrients. 2020 May 22;12(5):1506. doi: 10.3390/nu12051506.
PubMed 32455860Cheon E, Mattes RD. Interindividual variability in appetitive sensations and relationships between appetitive sensations and energy intake. Int J Obes (Lond). 2024 Apr;48(4):477-485. doi: 10.1038/s41366-023-01436-9. Epub 2023 Dec 22.
PubMed 38135701Elsworth RL, Hinton EC, Flynn AN, Merrell LH, Hamilton-Shield JP, Lawrence NS, Brunstrom JM. Development of Momentary Appetite Capture (MAC): A versatile tool for monitoring appetite over long periods. Appetite. 2024 Mar 1;194:107154. doi: 10.1016/j.appet.2023.107154. Epub 2023 Dec 9.
PubMed 38081544Zhu Y, Blundell JE, Holschuh NM, McLean R, Menon RS. Validation of a Mobile App-Based Visual Analog Scale for Appetite Measurement in the Real World: A Randomized Digital Clinical Trial. Nutrients. 2023 Jan 7;15(2):304. doi: 10.3390/nu15020304.
PubMed 36678176Flint A, Raben A, Blundell JE, Astrup A. Reproducibility, power and validity of visual analogue scales in assessment of appetite sensations in single test meal studies. Int J Obes Relat Metab Disord. 2000 Jan;24(1):38-48. doi: 10.1038/sj.ijo.0801083.
PubMed 10702749Godwin N, Roberts T, Hooshmand S, Kern M, Hong MY. Mixed Nuts May Promote Satiety While Maintaining Stable Blood Glucose and Insulin in Healthy, Obese, and Overweight Adults in a Two-Arm Randomized Controlled Trial. J Med Food. 2019 Apr;22(4):427-432. doi: 10.1089/jmf.2018.0127. Epub 2019 Mar 21.
PubMed 30897012Bermingham KM, May A, Asnicar F, Capdevila J, Leeming ER, Franks PW, Valdes AM, Wolf J, Hadjigeorgiou G, Delahanty LM, Segata N, Spector TD, Berry SE. Snack quality and snack timing are associated with cardiometabolic blood markers: the ZOE PREDICT study. Eur J Nutr. 2024 Feb;63(1):121-133. doi: 10.1007/s00394-023-03241-6. Epub 2023 Sep 15.
PubMed 37709944