Effects of Fasting on Body Mass Index and Gut Microbiome in Healthy Adults
In a randomized, controlled study, 38 healthy adults underwent a 5-day fasting intervention, which resulted in an acute reduction in body mass index, primarily due to fat loss. These effects were partially sustained at a 12-week follow-up. Additionally, fasting led to notable changes in gut microbiome composition and various metabolites.
- Tags
- #MSResearch
- Most relevant to
- —
Why it matters
Understanding how fasting affects body weight and gut microbiome could inform dietary strategies for metabolic health. However, the focus on healthy individuals limits applicability to those with metabolic disorders.
What this does not prove
This study only included healthy adults; effects on individuals with conditions like MS remain unreported. Furthermore, the findings have not been peer-reviewed, and the registered trial does not ensure effectiveness.
Next milestone
No next milestone was established from the available source.
Study facts
- Study design
- Interventional
- Participants / samples
- 38 · basis not reported
- Randomised
- Yes
- Controlled
- Yes
- Primary endpoint met
- Not reported
- Relevant MS type
- Not reported
- Publication date
- 2026-09-16
- Evidence reviewed
- Abstract only
- Regulatory approval
- Not reported
- Research areas
- Not classified
Original sources
- Primary evidenceMachine learning identifies microbiome and clinical predictors of sustained weight loss following prolonged fasting. ↗DOI: 10.1186/s13073-026-01765-0
Supporting passages (9)
study designIn a randomized, waitlist-controlled trial, 38 healthy adults completed a 5-day fasting intervention with 12-week follow-up (LEANER study).
subjectsMETHODS: In a randomized, waitlist-controlled trial, 38 healthy adults completed a 5-day fasting intervention with 12-week follow-up (LEANER study).
sample sizeMETHODS: In a randomized, waitlist-controlled trial, 38 healthy adults completed a 5-day fasting intervention with 12-week follow-up (LEANER study).
randomizedMETHODS: In a randomized, waitlist-controlled trial, 38 healthy adults completed a 5-day fasting intervention with 12-week follow-up (LEANER study).
controlledMETHODS: In a randomized, waitlist-controlled trial, 38 healthy adults completed a 5-day fasting intervention with 12-week follow-up (LEANER study).
primary endpointOutcomes included body mass index and body composition, gut microbiome composition, and plasma and fecal metabolites.
findingsFasting reduced body mass index acutely, predominantly driven by loss of fat mass, and these improvements partially persisted at 12 weeks.
publication datePublication date: 2026-09-16
limitationsTitle: Machine learning identifies microbiome and clinical predictors of sustained weight loss following prolonged fasting.
AI assessment, not yet reviewed by a person · version 1 · Community votes are separate from evidence review.