Cardiometabolic Effects of Pecan Snacking in Prediabetes

Inclusion Criteria:

* Age 25-65 years
* Prediabetes assessed by an HbA1c of 5.7-6.4% at screening
* BMI 25-40 kg/m2 at screening
* Low habitual nut consumption (\<3.5 oz-eq/week) assessed at the telephone screening
* Regularly eats snacks higher in saturated fat and/or added sugars assessed at the telephone screening

Exclusion Criteria:

* LDL-C ≥190 mg/dL at screening
* Hemoglobin \<13.2 g/dL at screening
* Fasting triglycerides \>350 mg/dL at screening
* ≥10% change in body weight within the 6 months prior to enrollment
* Blood pressure \>140/90 mmHg at screening
* Type 1 or type 2 diabetes
* Prescription of anti-hypertensive, lipid-lowering, or glucose-lowering drugs
* Intake of supplements or over-the-counter medications that affect the outcomes of interest (i.e., lipid, blood pressure, or glucose lowering; vitamin C or multi-vitamins containing vitamin C) and are unwilling to cease during the study period.
* History of liver, kidney, or autoimmune disease
* Prior cardiovascular event (e.g., stroke, heart attack)
* Current pregnancy or intention of pregnancy within the next 12 months
* Lactation within the prior 6 months
* Pecan allergy/intolerance/sensitivity/dislike
* Unwilling/unable to eat 1.5 oz of pecans every day as a snack during the duration of the study
* Antibiotic use within the prior 4 weeks
* Oral steroid use within the prior 4 weeks
* Use of tobacco or nicotine-containing products within the past 6 months
* History of cancer at any site within the past 10 years (eligible if ≥10 years without recurrence) or non-melanoma skin cancer within the past 5 years (eligible if ≥5 years without recurrence)
* Participation in another clinical trial within 60 days of baseline
* Unwilling to contact study staff before enrolling in other health-related research and avoid participating in any research that may interfere with this study.
* Currently following a restricted or weight-loss diet
* Prior bariatric surgery
* Intake of \>14 alcoholic drinks/week and/or not willing to avoid alcohol consumption for 48 hours prior to test visits
* Principal Investigator discretion related to the potential participant's ability to adhere to the study requirements, including being able to come to attend visits
* Does not speak and/or understand English
* Unwilling to refrain from donating blood or plasma during the study
* Weight \<110 lb
* If a potential participant takes thyroid medicine, abnormal thyroid stimulated hormone (TSH) concentration (TSH outside of normal range), or change in dose of thyroid medication within the last 6 months