Eating Almonds Before a Meal to Control Blood Sugar (NUTS)

Interindividual Variability in the Effect of Premeal Almond Supplementation on Glycemic Control - a Double Crossover Study

The goal of this study is to learn whether eating a small serving of almonds before meals can improve blood sugar control in adults who have early signs of problems with blood sugar regulation. The main questions it aims to answer are:

1. Does eating almonds before a meal reduce the rise in blood sugar after eating?
2. Do some people consistently benefit more than others from eating almonds before meals?

Study Overview

• Status: Not yet recruiting
• Conditions: Nutrition; Glucose Control; Prediabetes (Insulin Resistance, Impaired Glucose Tolerance); Precision Medicine
• Intervention / Treatment: Dietary supplement: Premeal almond ingestion

Detailed Description

Large rises in blood sugar after eating are an early warning sign of type 2 diabetes, and simple dietary strategies may help lower this risk. This study aims to understand whether eating a small serving of almonds before meals can help reduce postprandial blood sugar levels in adults who are at increased risk for developing type 2 diabetes. Participants will take part in two phases of the study: one conducted in a research clinic to carefully measure short-term blood sugar responses, and another conducted while participants follow a provided diet at home over a longer period. Sometimes participants will eat almonds before meals, and sometimes they will not. The study hypothesis is that eating almonds before meals will lower blood sugar rises after eating, and that some people will benefit more than others in a consistent way that can be observed both in the clinic and during everyday living.

• Study Type: Interventional
• Enrollment (Estimated): 25
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Kaja Falkenhain, PhD; Phone Number: 225-763-2558; Email: kaja.falkenhain@pbrc.edu

Study Locations

• United States
  • Louisiana
    • Baton Rouge, Louisiana, United States, 70808
      • Pennington Biomedical Research Center
      • Contact: Kaja Falkenhain, PhD; Phone Number: 225-763-2558; Email: kaja.falkenhain@pbrc.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Adults aged 25-50 years
• Females over 40 years must have had a cycle in the last 6 months
• Body mass index (BMI) at least 18.5 and at most 55.0 kg/m2
• Impaired blood glucose by at least one of the following criteria:
• Fasting blood glucose at least 100 mg/dL (5.6 mmol/L) and less than 125 mg/dL (6.9 mmol/L)
• HbA1c at least 5.7% and less than 6.5%
• Willing and able to comply with study foods
• Willing and able to ingest acetaminophen as part of study procedures
• Able to read, speak, and understand English

Exclusion Criteria:

• Weight change ≥5% in past 6 months, actively trying to lose weight, or unwilling to remain weight stable throughout the study based on self-report
• Recent history within past 12 months of medical provider-diagnosed cardiovascular, renal, or liver disease that required treatment
• Current or past diagnosis of cancer (except skin cancer) in the last 5 years
• Current or past diagnosis of type 1 or type 2 diabetes
• Recent history within past 12 months of medical provider-diagnosed gastrointestinal or neurological disorders if not managed/stable for at least 3 months (with or without treatment)
• Recent history within past 12 months of medical provider-diagnosed psychiatric disorders including eating disorders or severe depression if not managed/stable for at least 3 months (with or without treatment)
• Food allergies or other reasons preventing consumption of study foods
• Any glucose-lowering medication except biguanides (e.g., Metformin) if stable for at least 3 months or incretins (i.e., GLP-1RA-based) if stable for at least 3 months
• Current smoking or vaping or history of smoking or vaping in the past 6 months
• Binge and/or heavy drinking (i.e., >3 drinks on any given occasion and/or >7 drinks/week)
• Currently pregnant or planning to become pregnant or breastfeed in the next 3 months by self-report

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

8

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Randomization Sequence 1; One of the randomization sequences. Phase 1: MMTT+, MMTT-, MMTT+, MMTT- | Phase 2: SAD+, SAD-. In Phase 1, MMTT+ refers to a mixed meal tolerance test with premeal almond ingestion (active condition). MMTT- refers to a mixed meal tolerance test without premeal almond ingestion (control condition). In Phase 2, SAD+ refers to the 10-day controlled feeding diet period using a Standard American Diet with thrice daily premeal almond ingestion (active condition). SAD- refers to the 10-day controlled feeding diet period using a Standard American Diet without premeal almond ingestion (control condition).	Dietary supplement: Premeal almond ingestion; Premeal almond ingestion (18 g; ~100 kcal) 30 minutes prior to meal
Experimental: Randomization Sequence 2; One of the randomization sequences. Phase 1: MMTT-, MMTT+, MMTT-, MMTT+ | Phase 2: SAD+, SAD-. In Phase 1, MMTT+ refers to a mixed meal tolerance test with premeal almond ingestion (active condition). MMTT- refers to a mixed meal tolerance test without premeal almond ingestion (control condition). In Phase 2, SAD+ refers to the 10-day controlled feeding diet period using a Standard American Diet with thrice daily premeal almond ingestion (active condition). SAD- refers to the 10-day controlled feeding diet period using a Standard American Diet without premeal almond ingestion (control condition).	Dietary supplement: Premeal almond ingestion; Premeal almond ingestion (18 g; ~100 kcal) 30 minutes prior to meal
Experimental: Randomization Sequence 3; One of the randomization sequences. Phase 1: MMTT+, MMTT-, MMTT-, MMTT+ | Phase 2: SAD+, SAD-. In Phase 1, MMTT+ refers to a mixed meal tolerance test with premeal almond ingestion (active condition). MMTT- refers to a mixed meal tolerance test without premeal almond ingestion (control condition). In Phase 2, SAD+ refers to the 10-day controlled feeding diet period using a Standard American Diet with thrice daily premeal almond ingestion (active condition). SAD- refers to the 10-day controlled feeding diet period using a Standard American Diet without premeal almond ingestion (control condition).	Dietary supplement: Premeal almond ingestion; Premeal almond ingestion (18 g; ~100 kcal) 30 minutes prior to meal
Experimental: Randomization Sequence 4; One of the randomization sequences. Phase 1: MMTT-, MMTT+, MMTT+, MMTT- | Phase 2: SAD+, SAD-. In Phase 1, MMTT+ refers to a mixed meal tolerance test with premeal almond ingestion (active condition). MMTT- refers to a mixed meal tolerance test without premeal almond ingestion (control condition). In Phase 2, SAD+ refers to the 10-day controlled feeding diet period using a Standard American Diet with thrice daily premeal almond ingestion (active condition). SAD- refers to the 10-day controlled feeding diet period using a Standard American Diet without premeal almond ingestion (control condition).	Dietary supplement: Premeal almond ingestion; Premeal almond ingestion (18 g; ~100 kcal) 30 minutes prior to meal
Experimental: Randomization Sequence 5; One of the randomization sequences. Phase 1: MMTT+, MMTT-, MMTT+, MMTT- | Phase 2: SAD-, SAD+. In Phase 1, MMTT+ refers to a mixed meal tolerance test with premeal almond ingestion (active condition). MMTT- refers to a mixed meal tolerance test without premeal almond ingestion (control condition). In Phase 2, SAD+ refers to the 10-day controlled feeding diet period using a Standard American Diet with thrice daily premeal almond ingestion (active condition). SAD- refers to the 10-day controlled feeding diet period using a Standard American Diet without premeal almond ingestion (control condition).	Dietary supplement: Premeal almond ingestion; Premeal almond ingestion (18 g; ~100 kcal) 30 minutes prior to meal
Experimental: Randomization Sequence 6; One of the randomization sequences. Phase 1: MMTT-, MMTT+, MMTT-, MMTT+ | Phase 2: SAD-, SAD+. In Phase 1, MMTT+ refers to a mixed meal tolerance test with premeal almond ingestion (active condition). MMTT- refers to a mixed meal tolerance test without premeal almond ingestion (control condition). In Phase 2, SAD+ refers to the 10-day controlled feeding diet period using a Standard American Diet with thrice daily premeal almond ingestion (active condition). SAD- refers to the 10-day controlled feeding diet period using a Standard American Diet without premeal almond ingestion (control condition).	Dietary supplement: Premeal almond ingestion; Premeal almond ingestion (18 g; ~100 kcal) 30 minutes prior to meal
Experimental: Randomization Sequence 7; One of the randomization sequences. Phase 1: MMTT+, MMTT-, MMTT-, MMTT+ | Phase 2: SAD-, SAD+. In Phase 1, MMTT+ refers to a mixed meal tolerance test with premeal almond ingestion (active condition). MMTT- refers to a mixed meal tolerance test without premeal almond ingestion (control condition). In Phase 2, SAD+ refers to the 10-day controlled feeding diet period using a Standard American Diet with thrice daily premeal almond ingestion (active condition). SAD- refers to the 10-day controlled feeding diet period using a Standard American Diet without premeal almond ingestion (control condition).	Dietary supplement: Premeal almond ingestion; Premeal almond ingestion (18 g; ~100 kcal) 30 minutes prior to meal
Experimental: Randomization Sequence 8; One of the randomization sequences. Phase 1: MMTT-, MMTT+, MMTT+, MMTT-, | Phase 2: SAD-, SAD+. In Phase 1, MMTT+ refers to a mixed meal tolerance test with premeal almond ingestion (active condition). MMTT- refers to a mixed meal tolerance test without premeal almond ingestion (control condition). In Phase 2, SAD+ refers to the 10-day controlled feeding diet period using a Standard American Diet with thrice daily premeal almond ingestion (active condition). SAD- refers to the 10-day controlled feeding diet period using a Standard American Diet without premeal almond ingestion (control condition).	Dietary supplement: Premeal almond ingestion; Premeal almond ingestion (18 g; ~100 kcal) 30 minutes prior to meal

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postprandial glucose assessed during acute meal test	The primary endpoint will be the difference in plasma glucose incremental area under the curve (iAUC) assessed via intravenous blood sampling over three hours following a standardized mixed meal tolerance test (MMTT) with premeal ingestion of 18 g of almonds 30 minutes prior (MMTT+) compared to without (MMTT-). This effect will be averaged across the replicated acute challenge visits in the repeated crossover design.	Days 1-4: -35 minutes, -5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 120 minutes, 180 minutes relative to ingestion of premeal almonds at -30 minutes (if applicable) and the mixed meal tolerance test at 0 minutes.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Interindividual variability in the postprandial glucose assessed during acute meal test	Variability in response to the single-dose, acute premeal almond supplementation prior to the MMTT will be characterized according to previously established procedures using Pearson's correlation between the first and second replicate of the control-adjusted treatment effect (i.e., MMTT+ vs MMTT-). That is, the correlation between the difference in iAUC during the first crossover trial (i.e., iAUC during MMTT+ minus iAUC during MMTT-) and the difference in iAUC during the second crossover trial (i.e., iAUC during MMTT+ minus iAUC during MMTT-).	Days 1-4: -35 minutes, -5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 120 minutes, 180 minutes relative to ingestion of premeal almonds at -30 minutes (if applicable) and the mixed meal tolerance test at 0 minutes.
Consistency between acute glycemic response and longer-term glycemic control	Whether the individual glucose-lowering effect of the almond preload observed during the acute, repeated crossover, controlled in-laboratory MMTT predicts an individual's glycemic control during the 10-day, free-living, controlled-feeding phase in which almonds will be consumed thrice daily prior to each main meal on the background of a Standard American diet. We will evaluate this via the regression coefficient derived from a linear regression with the magnitude of the acute treatment effect in Days 1-4 (i.e., the difference in iAUC between MMTT+ and MMTT- averaged between both crossover trials) as the predictor and the magnitude of the treatment effect in Days 5-25 (i.e., the difference in average iAUC across the 10-day controlled feeding diet periods between MMTT+ and MMTT-) as the outcome.	Days 1-4: Days 1-4: -35 minutes, -5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 120 minutes, 180 minutes relative to ingestion of premeal almonds at -30 minutes (if applicable) and the mixed meal tolerance test at 0 minutes. Days 5-25

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Acute postprandial glucose	The difference in plasma glucose assessed via intravenous blood sampling over three hours following a standardized mixed meal tolerance test (MMTT) with premeal ingestion of 18 g of almonds 30 minutes prior (MMTT+) compared to without (MMTT-). This effect will be averaged across the replicated acute challenge visits in the repeated crossover design.	Days 1-4: -35 minutes, -5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 120 minutes, 180 minutes relative to ingestion of premeal almonds at -30 minutes (if applicable) and the mixed meal tolerance test at 0 minutes.
Acute postprandial gastric emptying	The difference in acetaminophen appearance (gastric emptying) assessed via intravenous blood sampling over three hours following a standardized mixed meal tolerance test (MMTT) with premeal ingestion of 18 g of almonds 30 minutes prior (MMTT+) compared to without (MMTT-). This effect will be averaged across the replicated acute challenge visits in the repeated crossover design.	Days 1-4: -35 minutes, -5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 120 minutes, 180 minutes relative to ingestion of premeal almonds at -30 minutes (if applicable) and the mixed meal tolerance test at 0 minutes.
Acute postprandial insulin	The difference in plasma insulin assessed via intravenous blood sampling over three hours following a standardized mixed meal tolerance test (MMTT) with premeal ingestion of 18 g of almonds 30 minutes prior (MMTT+) compared to without (MMTT-). This effect will be averaged across the replicated acute challenge visits in the repeated crossover design.	Days 1-4: -35 minutes, -5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 120 minutes, 180 minutes relative to ingestion of premeal almonds at -30 minutes (if applicable) and the mixed meal tolerance test at 0 minutes.
Acute postprandial glucagon-like peptide 1	The difference in plasma glucagon-like peptide 1 assessed via intravenous blood sampling over three hours following a standardized mixed meal tolerance test (MMTT) with premeal ingestion of 18 g of almonds 30 minutes prior (MMTT+) compared to without (MMTT-). This effect will be averaged across the replicated acute challenge visits in the repeated crossover design.	Days 1-4: -35 minutes, -5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 120 minutes, 180 minutes relative to ingestion of premeal almonds at -30 minutes (if applicable) and the mixed meal tolerance test at 0 minutes.
Cardiometabolic health - fasting glucose	The difference in the change of fasting plasma blood glucose from before to after a 10-day controlled feeding diet period with thrice daily premeal ingestion of 18 g of almonds 30 minutes to each meal (MMTT+) compared to without (MMTT-).	Days 5-25
Cardiometabolic health - fasting high-density lipoprotein cholesterol	The difference in the change of fasting high-density lipoprotein cholesterol from before to after a 10-day controlled feeding diet period with thrice daily premeal ingestion of 18 g of almonds 30 minutes to each meal (MMTT+) compared to without (MMTT-).	Days 5-25
Cardiometabolic health - fasting low-density lipoprotein cholesterol	The difference in the change of fasting low-density lipoprotein cholesterol from before to after a 10-day controlled feeding diet period with thrice daily premeal ingestion of 18 g of almonds 30 minutes to each meal (MMTT+) compared to without (MMTT-).	Days 5-25
Cardiometabolic health - fasting total cholesterol	The difference in the change of fasting total cholesterol from before to after a 10-day controlled feeding diet period with thrice daily premeal ingestion of 18 g of almonds 30 minutes to each meal (MMTT+) compared to without (MMTT-).	Days 5-25
Cardiometabolic health - fasting insulin	The difference in the change of fasting plasma insulin from before to after a 10-day controlled feeding diet period with thrice daily premeal ingestion of 18 g of almonds 30 minutes to each meal (MMTT+) compared to without (MMTT-).	Days 5-25
Cardiometabolic health - fasting glucagon-like peptide 1	The difference in the change of fasting glucagon-like peptide 1 from before to after a 10-day controlled feeding diet period with thrice daily premeal ingestion of 18 g of almonds 30 minutes to each meal (MMTT+) compared to without (MMTT-).	Days 5-25
Cardiometabolic health - fasting C-reactive protein	The difference in the change of fasting C-reactive protein from before to after a 10-day controlled feeding diet period with thrice daily premeal ingestion of 18 g of almonds 30 minutes to each meal (MMTT+) compared to without (MMTT-).	Days 5-25
Cardiometabolic health - 24-hour glucose	The difference in average 24-hour glucose assessed via CGM during a 10-day controlled feeding diet period with thrice daily premeal ingestion of 18 g of almonds 30 minutes to each meal (MMTT+) compared to without (MMTT-).	Days 5-25
Cardiometabolic health - glucose incremental area under the curve	The difference in average meal blood glucose incremental area under the curve (iAUC) assessed via CGM during a 10-day controlled feeding diet period with thrice daily premeal ingestion of 18 g of almonds 30 minutes to each meal (MMTT+) compared to without (MMTT-).	Days 5-25
Cardiometabolic health - glucose area under the curve	The difference in average meal blood glucose area under the curve (AUC) assessed via CGM during a 10-day controlled feeding diet period with thrice daily premeal ingestion of 18 g of almonds 30 minutes to each meal (MMTT+) compared to without (MMTT-).	Days 5-25
Cardiometabolic health - glucose standard deviation	The difference in average blood glucose standard deviation (SD) assessed via CGM during a 10-day controlled feeding diet period with thrice daily premeal ingestion of 18 g of almonds 30 minutes to each meal (MMTT+) compared to without (MMTT-).	Days 5-25
Cardiometabolic health - glucose coefficient of variation	The difference in average blood glucose coefficient of variation (CV) assessed via CGM during a 10-day controlled feeding diet period with thrice daily premeal ingestion of 18 g of almonds 30 minutes to each meal (MMTT+) compared to without (MMTT-).	Days 5-25
Cardiometabolic health - glucose time in range	The difference in average glucose time in range assessed via CGM during a 10-day controlled feeding diet period with thrice daily premeal ingestion of 18 g of almonds 30 minutes to each meal (MMTT+) compared to without (MMTT-).	Days 5-25

Collaborators and Investigators

• Sponsor: Pennington Biomedical Research Center

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): March 1, 2028
• Study Completion (Estimated): July 1, 2028

Study Registration Dates

• First Submitted: May 8, 2026
• First Submitted That Met QC Criteria: May 16, 2026
• First Posted (Actual): May 22, 2026

Study Record Updates

• Last Update Posted (Actual): May 22, 2026
• Last Update Submitted That Met QC Criteria: May 16, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Prediabetes; Insulin Resistance; Nutrition; Precision Medicine; Impaired Glucose Tolerance; Glucose Control; Precision Nutrition
• Additional Relevant MeSH Terms: Endocrine System Diseases; Metabolic Diseases; Glucose Metabolism Disorders; Diabetes Mellitus; Hyperinsulinism; Hyperglycemia; Nutritional and Metabolic Diseases; Insulin Resistance; Prediabetic State; Glucose Intolerance
• Other Study ID Numbers: PBRC 2026-009

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Data will be shared upon reasonable request to the study investigator and upon successful execution of a data transfer/sharing agreement.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No