Precision Diets for Diabetes Prevention

NCT03919877 | Completed Results

• 2 other identifiers: 438835RM1HG007735-09
• Study Type: interventional
• Target: 115
• Locations: 1 country
• Sites: 1

Brief Summary

With this study the investigators want to understand the physiological differences for people developing pre-diabetes and diabetes. The investigators hypothesize that different individuals go through different paths in the development of the disease. By understanding the personal mechanism for developing disease, the investigators will find a personalized approach to prevent that development. The investigators are also hoping to be able to find a biomarker that will pinpoint to the particular defect and thus, diagnose the problem at an earlier stage and have the information to give personalized diet recommendations to prevent the development of diabetes more effectively.

Conditions

Pre Diabetes; Insulin Resistance; Diabetes Mellitus, Type 2

Outcome Measures

Primary Outcomes (2)

• Change in Glycemic Control as Measured by Change Blood Sugar Values

  Change in glycemic control measured from baseline through all phases of study, stratified according food type and metabolic sub-type. Glycemic control is derived from continuous glucose monitor (CGM) data and expressed in milligrams/deciliter.

  Assessed at a meal (2 to 6 weeks after baseline), starting just prior eating, for a period of 3 hours

• Area Under the Receiver Operating Characteristic (ROC) Curve - Classification of Metabolic Subphenotype

  Classify metabolic subphenotype in individuals without diabetes using a machine learning algorithm applied to the glucose time-series response generated by a 16-point (blood draws) oral glucose tolerance testing (OGTT) done in the clinical research center and at home (using CGM). Participants were categorized as insulin sensitive (IS) if teady state plasma glucose (SSPG) was \<120 mg dl-1 and insulin resistant (IR) if their SSPG was ≥120 mg dl-1. For this analysis, disposition index (DI) \< 1.58 indicates dysfunctional β-cell function, whereas DI ≥ 1.58 indicates normal β-cell function.

  Baseline (Day 1)

Secondary Outcomes (1)

• Change in Area Under the Curve (AUC) of Blood Glucose Level

  Assessed at a meal (2 to 6 weeks after baseline), starting just prior eating, for a period of 3 hours

Study Arms (1)

Optimizing Diet for Glycemic Control

OTHER

Phase 1: Metabolic testing will include 3 metabolic tests: 1. The Oral Glucose Tolerance Test. The participant will wear the CGM while undergoing the OGTT + will be asked to repeat the test at home twice. 2. The Insulin Sensitivity Test (Steady State Plasma Glucose). This test is designed to measure how well cells remove glucose from the blood in response to insulin. 3. The Isoglycemic Intravenous Glucose Infusion (IIGI). This test is designed to measure the incretin hormone effect. Phase 2: Participants follow their own diet while using the CGM. Participants are provided with 5-10 standardized foods to test during this phase. Phase 3: Participants are provided with additional standardized foods and counseled to continue their own diet during this phase. Phase 4: Participants are counseled on reducing or limiting the foods that caused glucose spikes and they are also counseled on macronutrient composition of their diet based on lipid profile.

Other: Dietary; Other: Oral Food Challege

Interventions

Dietary OTHER

Dietary counseling based on results of CGM analyses.

Optimizing Diet for Glycemic Control

Oral Food Challege OTHER

Participants ate a variety of foods, to assess their impact on blood sugars.

Optimizing Diet for Glycemic Control

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Be 18 years of age or older;
• Not be pregnant, if female;

You may not qualify if:

• Have major organ disease, hypertension defined as \>160/100, pregnant/lactating, diabetogenic medications, malabsorptive disorders like celiac sprue, others, heavy alcohol use, use of weight loss medications or specific diets, weight change \> 2 kg in the last three weeks, history of bariatric surgery.
• Any medical condition that physicians believe would interfere with study participation or evaluation of results.
• Mental incapacity a nd/or cognitive impairment on the part of the patient that would preclude adequate understanding of, or cooperation with, the study protocol.

Sponsors & Collaborators

• Stanford University: lead
• National Human Genome Research Institute (NHGRI): collaborator

Study Sites (1)

Stanford University

Stanford, California, 94304, United States

Location

Related Publications (3)

• Wu Y, Ehlert B, Metwally AA, Perelman D, Park H, Brooks AW, Abbasi F, Michael B, Celli A, Bejikian C, Ayhan E, Lu Y, Lancaster SM, Hornburg D, Ramirez L, Bogumil D, Pollock S, Wong F, Bradley D, Gutjahr G, Rangan ES, Wang T, McGuire L, Venkat Rangan P, Raeder H, Shipony Z, Lipson D, McLaughlin T, Snyder MP. Individual variations in glycemic responses to carbohydrates and underlying metabolic physiology. Nat Med. 2025 Jul;31(7):2232-2243. doi: 10.1038/s41591-025-03719-2. Epub 2025 Jun 4.

  PMID: 40467897 RESULT

• Metwally AA, Perelman D, Park H, Wu Y, Jha A, Sharp S, Celli A, Ayhan E, Abbasi F, Gloyn AL, McLaughlin T, Snyder MP. Prediction of metabolic subphenotypes of type 2 diabetes via continuous glucose monitoring and machine learning. Nat Biomed Eng. 2025 Aug;9(8):1222-1239. doi: 10.1038/s41551-024-01311-6. Epub 2024 Dec 23.

  PMID: 39715896 RESULT

• Park H, Metwally AA, Delfarah A, Wu Y, Perelman D, Mayer C, McGinity C, Rodgar M, Celli A, McLaughlin T, Mignot E, Snyder M. High-resolution lifestyle profiling and metabolic subphenotypes of type 2 diabetes. NPJ Digit Med. 2025 Jun 11;8(1):352. doi: 10.1038/s41746-025-01728-6.

  PMID: 40500312 DERIVED

MeSH Terms

Conditions

Glucose Intolerance; Insulin Resistance; Diabetes Mellitus, Type 2

Interventions

Diet

Condition Hierarchy (Ancestors)

Hyperglycemia; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Hyperinsulinism; Diabetes Mellitus; Endocrine System Diseases

Intervention Hierarchy (Ancestors)

Nutritional Physiological Phenomena; Diet, Food, and Nutrition; Physiological Phenomena

Results Point of Contact

• Title: Michael Snyder, Ph.D.
• Organization: Stanford University

mpsnyder@stanford.edu

(650) 723-4668

Study Officials

• Michael P Snyder, PhD

  Stanford University

  PRINCIPAL INVESTIGATOR

• Tracey McLaughlin, MD

  Stanford University

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Chair, Genetics Department

Study Record Dates

• First Submitted: December 20, 2018
• First Posted: April 18, 2019
• Study Start: May 24, 2018
• Primary Completion: October 18, 2023
• Study Completion: October 18, 2023
• Last Updated: May 22, 2026
• Results First Posted: May 22, 2026

Record last verified: 2026-04

Locations

US (1)