Dietary patterns for weight and glycemic management in persons with type 1 diabetes: a meta-analysis of clinical trials

BackgroundMedical nutrition therapy is fundamental for managing glycemia and weight in type 1 diabetes, yet dietary guidance specific to this population and relevant subgroups is lacking. PurposeWe synthesized the interventional literature investigating diet patterns for glycemic and weight management in youth and adults with type 1 diabetes, with attention to interindividual variation that suggests the need for precision approaches. Data SourcesAMED, CINAHL, Cochrane Library, Ovid MEDLINE, Ovid Embase, Google Scholar, and Web of Science Core Collection were searched from January 2011 to June 2024. Study SelectionClinical trials [≥]4 weeks with [≥]10 youth and/or adults diagnosed with type 1 diabetes [≥]6 months prior and reported HbA1c or weight were included. Data SynthesisTwelve studies with 668 participants were included. Data were pooled by random-effects models for HbA1c and weight. Studies with insufficient data and subgroup differences were narratively synthesized per Synthesis Without Meta-analysis guidelines. Pooled results of very low to moderate certainty evidence showed no advantage of any particular diet pattern relative to routine care in randomized trials. Very low-quality evidence from single-arm low carbohydrate trials suggested improved HbA1c over time (-0.63% [95%CI -0.99, -0.27]; -6.0 mmol/mol [-10.8, -3.0]). Wide pooled confidence intervals demonstrated between-person heterogeneity; however, stratification of results by participant characteristics was rarely performed. LimitationsLimited evidence precluded subgroup analyses that can inform precision nutrition approaches. ConclusionsRandomized trials designed to investigate treatment response heterogeneity are needed to determine whether precision nutrition therapies optimize glycemia and weight in persons with type 1 diabetes. Disclosure SummaryLaura Nally receives research support from the National Institutes of Health and is a consultant for Medtronic, WebMD, and Calm. Jennifer Sherr serves, or has served, on advisory panels for Bigfoot Biomedical, Cecelia Health, Insulet Corporation, Mannkind, Medtronic Diabetes, StartUp Health Diabetes Moonshot, and Vertex. Dr. Sherr has served as a consultant to Abbott Diabetes, Bigfoot Biomedical, Insulet, Medtronic Diabetes, and Zealand. Yale School of Medicine has received research support for Dr. Sherr from Abbott Diabetes, JAEB Center for Health Research, JDRF, Insulet, Medtronic, NIH, and Prevention Bio. Chantal Mathieu serves or has served on the advisory panel for Novo Nordisk, Sanofi, Eli Lilly and Company, Novartis, Dexcom, Boehringer Ingelheim, Bayer, Roche, Abbott, Medtronic, Insulet, Biomea Fusion, SAB Bio and Vertex. Financial compensation for these activities has been received by KU Leuven; KU Leuven has received research support for Chantal Mathieu from Medtronic, Novo Nordisk, and Sanofi; Chantal Mathieu serves or has served on the speakers bureau for Novo Nordisk, Sanofi, Eli Lilly and Company, Medtronic, Dexcom, Insulet, Abbott, Vertex and Boehringer Ingelheim. Financial compensation for these activities has been received by KU Leuven. Irl Hirsch reports research funding from Tandem and Dexcom; and consulting fees from Abbott, Roche, GWave, and Vertex. Lori Laffel reports consulting for Dexcom, Boehringer Ingelheim, Medtronic, Provention Bio, Sanofi, Medtronic, Sequel MedTech, Vertex, and Tandem Diabetes. Peter Gottlieb has served as an advisor to Viacyte/Vertex, Imcyse, JDRF T1D Fund, and GentiBio; has received research support from Novo Nordisk, Imcyse, Novartis, Mercia/Nova, Provention Bio, ActoBio Therapeutics, Helmsley Foundation, JDRF, and NIH; and is a co-founder, Chief Medical Officer, and shareholder of ImmunoMolecular Therapeutics, Inc. Mustafa Tosur served as an advisory board member for Provention Bio in 2020 and 2021. Richard Pratley has received the following (thru 12/31/2023 directed to his institution; as of 1/1/2024 directed to Dr. Pratley personally): speaker fees from Lilly, Merck and Novo Nordisk; consulting fees from Bayer AG, Bayer HealthCare Pharmaceuticals, Inc., Corcept Therapeutics Incorporated, Dexcom, Endogenex, Inc., Gasherbrum Bio, Inc., Genprex, Getz Pharma, Hanmi Pharmaceutical Co., Hengrui (USA) Ltd., Intas Pharmaceuticals, Inc., Lilly, Merck, Novo Nordisk, Pfizer, Rivus Pharmaceuticals Inc., Sanofi, and Sun Pharmaceutical Industries; and grants from Biomea Fusion, Carmot Therapeutics, Dompe, Endogenex, Inc., Fractyl, Lilly, Novo Nordisk, and Sanofi. All other authors report no conflict of interest.