Aug 20, 2025
Chronodisruption and Post-Bariatric Weight Outcomes: A Scoping Review Protocol
- Athanasios Pantelis1,
- Zoe Pafili2,
- Vasiliki Tseliou2,
- Dimitris P. Lapatsanis1
- 1Athens Medical Group, Psychiko Clinic;
- 2Evaggelismos General Hospital of Athens
Protocol Citation: Athanasios Pantelis, Zoe Pafili, Vasiliki Tseliou, Dimitris P. Lapatsanis 2025. Chronodisruption and Post-Bariatric Weight Outcomes: A Scoping Review Protocol. protocols.io https://dx.doi.org/10.17504/protocols.io.3byl46q88go5/v1
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: August 20, 2025
Last Modified: August 20, 2025
Protocol Integer ID: 225065
Keywords: chronodisruption, bariatric surgery, metabolic surgery, weight outcomes, sleep, chronotype, social jetlag, meal timing, shift work, light at night, bariatric surgery, gastric bypass, anastomosis gastric bypass, weight regain, excess weight loss, weight outcome, weight gain, insufficient weight loss, recurrent weight gain, total weight loss, gastrectomy, sleep timing, disturbances in sleep duration, review maps evidence on whether chronodisruption, sleep quality, sleep duration, meal timing, body mass index, chronodisruption, bmi
Abstract
This scoping review maps evidence on whether chronodisruption—defined as disturbances in sleep duration, sleep quality, sleep timing, chronotype, social jetlag (SJL), meal timing/chrononutrition, shift work, and light at night (LAN)—is associated with post-metabolic and bariatric surgery (MBS) weight outcomes (percent excess weight loss [%EWL], percent total weight loss [%TWL], body mass index [BMI] change, insufficient weight loss, and weight gain [recurrent weight gain (RWG), also termed weight regain (WR)]). Procedures include but are not limited to Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), and one-anastomosis gastric bypass (OAGB).
Guidelines
Objectives / Review Questions
1. Which chronodisruption exposures have been studied in adults undergoing MBS?
2. How have these exposures been measured (e.g., PSQI, actigraphy, MEQ, social jetlag computation, meal-timing thresholds, shift-work status, LAN measures)?
3. What postoperative weight outcomes have been reported, and what is the direction/consistency of associations?
Population–Concept–Context (PCC)
- Population: Adults (≥18 years) undergoing MBS (e.g., RYGB, SG, OAGB).
- Concept: Chronodisruption exposures: sleep duration/quality/timing; chronotype; SJL; meal timing/chrononutrition; shift work; LAN.
- Context: Associations with postoperative weight outcomes (%EWL, %TWL, BMI change, insufficient weight loss, WR/RWG).
Eligibility Criteria
Inclusion
- Adult bariatric/metabolic surgery cohorts or comparative studies.
- At least one chronodisruption exposure measured (e.g., Pittsburgh Sleep Quality Index [PSQI], actigraphy, Morningness–Eveningness Questionnaire [MEQ], computed SJL, explicit meal-timing thresholds such as “main meal before vs after 15:00”, shift-work status, LAN by self-report or objective light).
- At least one postoperative weight outcome: %EWL, %TWL, BMI change, insufficient weight loss, or WR/RWG.
- Any country, setting, or surgery type.
Exclusion
- Pediatric cohorts; non-bariatric samples.
- Studies reporting only pre/post sleep or obstructive sleep apnoea (OSA) changes without relating a chronodisruption exposure to weight outcomes.
- Editorials, commentaries, and case reports.
- Genetics-only analyses (e.g., CLOCK variants) unless a behavioral chronodisruption exposure is also modeled.
- Non-human experiments (retained separately as mechanistic context; not synthesized with human outcomes).
Study Records and Workflow
Roles
- Search 6 screening: AGP, VT (independent).
- Data charting: AGP, ZP (independent).
- Adjudication: DPL (referee).
Screening workflow
4. Title/abstract screening against eligibility criteria.
5. Full-text assessment for potentially eligible records.
6. Cohort de-duplication: when multiple reports use the same cohort, retain the most comprehensive/longest-follow-up analysis; cite companions narratively.
Data Charting
We will chart data using a piloted form with the fields below. A short calibration exercise on 3–5 papers will harmonize coding before charting the full sample.
| Category | Author | Year | Reference (journal; year; vol(issue):pages) | Design | n | Exposure | Outcome | Key findings |
|---|---|---|---|---|---|---|---|---|
| Sleep timing / Chronotype / SJL / Meal timing / Shift work / LAN | Surname Initials | Year | Journal; Year; Volume (Issue): Pages | Prospective cohort / Retrospective / Cross-sectional | n | Instrument/definition (e.g., PSQI, actigraphy, MEQ, SJL calc, meal-time threshold, shift-work, LAN) | Weight metric 6 timepoint (%EWL, %TWL, BMI; WRG) | ≤2–3 lines; direction/consistency |
Critical Appraisal
Formal risk-of-bias assessment is not required for scoping reviews. For clinical interpretability, we will provide a concise Newcastle–Ottawa Scale (NOS)–style summary for cohort/retrospective designs and an adapted read-across for cross-sectional studies. Quality appraisal will not be used as an exclusion criterion.
Synthesis of Results
We will provide a descriptive mapping by chronodisruption domain (sleep duration/quality/timing; chronotype; SJL; meal timing/chrononutrition; shift work; LAN), summarizing measurement approaches, surgery types, weight outcomes, and directions of association. No meta-analysis will be conducted. Results will include a PRISMA-ScR flow diagram, the evidence table (with the charted fields above), and a narrative summary of gaps and priorities (e.g., objective exposure assessment, standardized WRG definitions, longer follow-up).
Outcomes and Prioritization
Where multiple weight metrics are reported, we will preferentially chart percent excess weight loss (%EWL) or percent total weight loss (%TWL) near 12 months and the longest available follow-up thereafter. WR/RWG definitions will be recorded verbatim.
Amendments
Any protocol amendments (scope, sources, eligibility) will be time-stamped in Protocols.io and reflected in the final manuscript (Methods and Supplement).
Troubleshooting
Eligibility Criteria
Screen studies for inclusion based on the following criteria: (a) Adult bariatric/metabolic surgery cohorts or comparative studies; (b) At least one chronodisruption exposure measured (e.g., Pittsburgh Sleep Quality Index [PSQI], actigraphy, Morningness–Eveningness Questionnaire [MEQ], computed SJL, explicit meal-timing thresholds such as “main meal before vs after 15:00”, shift-work status, LAN by self-report or objective light); (c) At least one postoperative weight outcome: %EWL, %TWL, BMI change, insufficient weight loss, or WR/RWG; (d) Any country, setting, or surgery type.
Exclude studies based on the following criteria: (a) Pediatric cohorts; non-bariatric samples; (b) Studies reporting only pre/post sleep or obstructive sleep apnoea (OSA) changes without relating a chronodisruption exposure to weight outcomes; (c) Editorials, commentaries, and case reports; (d) Genetics-only analyses (e.g., CLOCK variants) unless a behavioral chronodisruption exposure is also modeled; (e) Non-human experiments (retained separately as mechanistic context; not synthesized with human outcomes).
Information Sources
Identify studies using the following information sources: (a) MEDLINE (via PubMed); (b) Embase (Elsevier); (c) Backward/forward citation chasing of included studies and key reviews.
Search Strategy
Conduct the literature search in PubMed/MEDLINE (run 19 Aug 2025; no date/language limits at search stage) and Embase (Elsevier). Use the following search strategies:
For PubMed, use the following query: ("bariatric surgery"[tiab] OR "metabolic surgery"[tiab] OR "Roux-en-Y"[tiab] OR "sleeve gastrectomy"[tiab] OR "gastric bypass"[tiab]) AND (chronotype OR circadian OR "social jetlag" OR "shift work" OR "meal timing" OR chrononutrition OR "sleep duration" OR insomnia OR "sleep quality" OR "light at night") AND (weight regain OR "insufficient weight loss" OR "weight loss maintenance" OR BMI OR "excess weight loss" OR "recurrent weight gain")
For Embase, use the following free-text block (adapt to your interface; consider adding Emtree terms): (ti,ab,kw:("bariatric surgery" OR "metabolic surgery" OR "Roux-en-y" OR "sleeve gastrectomy" OR "gastric bypass")) AND (ti,ab,kw:(chronotype OR circadian OR "social jetlag" OR "shift work" OR "meal timing" OR chrononutrition OR "sleep duration" OR insomnia OR "sleep quality" OR "light at night")) AND (ti,ab,kw:("weight regain" OR "insufficient weight loss" OR "weight loss maintenance" OR BMI OR "excess weight loss" OR "recurrent weight gain"))
Export records to a reference manager and deduplicate prior to screening.
Study Records and Workflow
Assign roles for the review process as follows: (a) Search 6 screening: AGP, VT (independent); (b) Data charting: AGP, ZP (independent); (c) Adjudication: DPL (referee).
Screen studies using the following workflow: 4. Title/abstract screening against eligibility criteria. 5. Full-text assessment for potentially eligible records. 6. Cohort de-duplication: when multiple reports use the same cohort, retain the most comprehensive/longest-follow-up analysis; cite companions narratively.
Data Charting
Chart data using a piloted form with the following fields: Category, Author, Year, Reference (journal; year; vol(issue):pages), Design, n, Exposure, Outcome, Key findings. Conduct a short calibration exercise on 3–5 papers to harmonize coding before charting the full sample.
Critical Appraisal
Do not conduct formal risk-of-bias assessment for scoping reviews. For clinical interpretability, provide a concise Newcastle–Ottawa Scale (NOS)–style summary for cohort/retrospective designs and an adapted read-across for cross-sectional studies. Do not use quality appraisal as an exclusion criterion.
Synthesis of Results
Provide a descriptive mapping by chronodisruption domain (sleep duration/quality/timing; chronotype; SJL; meal timing/chrononutrition; shift work; LAN), summarizing measurement approaches, surgery types, weight outcomes, and directions of association. Do not conduct meta-analysis. Include a PRISMA-ScR flow diagram, the evidence table (with the charted fields), and a narrative summary of gaps and priorities (e.g., objective exposure assessment, standardized WRG definitions, longer follow-up).
Outcomes and Prioritization
When multiple weight metrics are reported, preferentially chart percent excess weight loss (%EWL) or percent total weight loss (%TWL) near 12 months and the longest available follow-up thereafter. Record WR/RWG definitions verbatim.
Amendments
Time-stamp any protocol amendments (scope, sources, eligibility) in Protocols.io and reflect them in the final manuscript (Methods and Supplement).
Ethics & Dissemination
Note that no human subjects are involved. Submit findings to a peer-reviewed journal and present at relevant meetings.
Conflicts of Interest & Funding
Disclose conflicts and funding in the final manuscript.
Acknowledgements
Authors will disclose conflicts and funding in the final manuscript.
Abbreviations
TWL, percent total weight loss; EWL, percent excess weight loss; BMI, body mass index; MBS, metabolic and bariatric surgery; RYGB, Roux-en-Y gastric bypass; SG, sleeve gastrectomy; OAGB, one-anastomosis gastric bypass; PSQI, Pittsburgh Sleep Quality Index; MEQ, Morningness–Eveningness Questionnaire; SJL, social jetlag; LAN, light at night; OSA, obstructive sleep apnoea; RWG, recurrent weight gain; WR, weight regain.