Associations between diet composition, dietary pattern, and weight outcomes after bariatric surgery: a systematic review

H C Cheung; E Strodl; J Musial; H L MacLaughlin; A Byrnes; C-A Lewis; L J Ross

doi:10.1038/s41366-023-01333-1

Associations between diet composition, dietary pattern, and weight outcomes after bariatric surgery: a systematic review

Int J Obes (Lond). 2023 Sep;47(9):764-790. doi: 10.1038/s41366-023-01333-1. Epub 2023 Jul 6.

Authors

H C Cheung¹, E Strodl², J Musial³, H L MacLaughlin^{4

5}, A Byrnes⁵, C-A Lewis⁵, L J Ross⁴

Affiliations

¹ Queensland University of Technology, School of Exercise and Nutrition Sciences, Faculty of Health, Brisbane, QLD, Australia. h8.cheung@hdr.qut.edu.au.
² Queensland University of Technology, School of Psychology and Counselling, Faculty of Health, Brisbane, QLD, Australia.
³ Department of Nutrition and Dietetics, Clinical Support Services, Princess Alexandra Hospital, Brisbane, QLD, Australia.
⁴ Queensland University of Technology, School of Exercise and Nutrition Sciences, Faculty of Health, Brisbane, QLD, Australia.
⁵ Nutrition Research Collaborative, Department of Dietetics and Food Service, Royal Brisbane and Women's Hospital, Herston, Brisbane, QLD, Australia.

Abstract

Introduction: Literature describing the impact of dietary intake on weight outcomes after bariatric surgery has not been synthesized. This study aimed to synthesize the evidence regarding any association between diet composition and weight outcomes post-bariatric surgery.

Methods: CINAHL, Cochrane, Embase, MEDLINE and Scopus were searched for adult studies up to June 2021 that assessed any association between dietary intakes (≥1-macronutrient, food group, or dietary pattern) and weight outcomes at 12-months or longer after bariatric surgery. Risk of bias and quality assessments were conducted using the Scottish Intercollegiate Guidelines Network checklists and the NHMRC's Level of Evidence and Grades for Recommendations. Study findings were presented according to the time of post-surgery dietary intake assessment (≤12months, between 12 and 24 months, ≥24months).

Results: 5923 articles were identified, 260 were retrieved for full text screening, and 36 were eligible for inclusion (9 interventional including five randomized-controlled trials, and 27 observational cohort studies; sample sizes: 20-1610; total sample: 5065; follow-up periods: 1 year-12 years; level of evidence: II to IV, risk of bias: low to high). Findings on the association between long-term weight outcomes and dietary composition up to 24-months were mixed. After 24-months, studies consistently suggested no significant associations between weight loss and macronutrient composition or core food group patterns, or between carbohydrate, protein or food group patterns and weight recurrence. A single cohort study reported a weak association between diet quality score and weight-recurrence after 24-months.

Conclusion: There was no strong evidence to support significant associations between diet composition and weight outcomes post-bariatric surgery. The heterogeneity in study design and quality may reduce generalizability to external populations. Individualized dietary recommendations may be useful to support long-term post-surgery weight outcomes. More studies are needed to define and measure diet quality in this patient cohort.

Registration: PROSPERO (CRD42021264120).

Publication types

Systematic Review
Review
Research Support, Non-U.S. Gov't

MeSH terms

Adult
Bariatric Surgery*
Cohort Studies
Diet
Food
Humans
Nutrients