Does a high-fibre snack bar reduce post-meal hunger compared with a typical UK snack bar?

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This remote, 5-day study compares two snack bars in healthy adults to see if the high-fibre intervention bar affects hunger, energy intake, and eating behavior the same day. Participants will consume two snack bars on two test days, separated by two days, after a pre-specified overnight fast. They will complete short online surveys before breakfast to capture dietary habits, hunger, mood, energy, and alertness. The trial uses a control bar that mirrors the average nutrient profile of snacks sold in the UK, to attribute effects to the intervention formulation. The primary question is whether the intervention bar lowers subjective postprandial hunger compared with the control bar.

Why it matters

Who can join: the full rules

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

Where it's running

• ZOE limited
  London, United Kingdom Recruiting

Study contacts

• Principal investigator: Berry E Sarah, Professor — King's College London
• Study coordinator: Study Co-ordinator
• Email: smarteats-trial@joinzoe.com
• Phone: +44 (0)330 818 8669

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.