Tree Nut Consumption to Reduce Abdominal Adiposity

Not Applicable

Completed

• Conditions: Millenials; Risk for Metabolic Syndrome
• Interventions: Other: High Carbohydrate or Tree Nut Food Snacks

• Registration Number: NCT03969264
• Lead Sponsor: Vanderbilt University Medical Center

Brief Summary

A major contributing factor to the rising waist circumference of U.S. young adults is the increase in snacking behavior. Both the frequency of snacking during the day and the percentage of adults who engage in snacking has risen; national data indicates snacking comprises 15-25% of the total daily caloric intake of young and middle-aged adults. The overarching hypothesis, based on significant preliminary data, is that the quantity and metabolic function of abdominal fat is a key intermediary factor by which greater tree nut consumption reduces ectopic lipid storage (including the accumulation of intra-abdominal \[visceral\] fat), improves fatty acid and lipoprotein metabolism, reduces systemic inflammation and insulin resistance, and thus, reduces risk for MetS in millennial-generation age individuals.

Detailed Description

A major contributing factor to the rising waist circumference of U.S. young adults is the increase in snacking behavior. Both the frequency of snacking during the day and the percentage of adults who engage in snacking has risen; national data indicates snacking comprises 15-25% of the total daily caloric intake of young and middle-aged adults. Unfortunately, current typical snack items are energy rich, providing high intake of carbohydrates and sugars, as opposed to nuts that are nutrient rich. In prior work with middle-aged adults, the investigators found that consuming tree nuts daily as between-meal snacks for a period of 16 weeks significantly reduced intra-abdominal (visceral) fat and waist circumference, which was associated with altered plasma fatty acid profiles and higher fatty acid oxidation rates. Based on prior findings, the investigators propose to determine whether consuming mixed tree nuts as replacement for typical high carbohydrate snacks reduces abdominal obesity and waist circumference in millennials at risk for MetS. The overarching hypothesis, based on significant preliminary data, is that the quantity and metabolic function of abdominal fat is a key intermediary factor by which greater tree nut consumption reduces ectopic lipid storage (including the accumulation of intra-abdominal \[visceral\] fat), improves fatty acid and lipoprotein metabolism, reduces systemic inflammation and insulin resistance, and thus, reduces risk for MetS in millennial-generation age individuals. The hypothesis will be tested by determining: 1) the effect of consuming mixed tree nuts as daily snacks for 16 weeks on waist circumference and the quantity of abdominal fat (subcutaneous and visceral fat); 2) the effect of consuming mixed tree nuts as daily snacks for 16 weeks on circulating fatty acid profiles, glucose tolerance and insulin resistance, circulating lipids and lipoproteins, and circulating markers of inflammation; and 3) the effect of consuming mixed tree nuts as daily snacks for 16 weeks on abdominal tissue expression of genes that regulate inflammation, insulin resistance, and cardiometabolic mediators of MetS risk.

Basic Information
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Recruitment & Eligibility
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Study & Design
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Trial Locations

Study Timeline

• Study First Submitted: 2019-05-23
• Study First Submitted QC: 2019-05-28
• Study First Posted: 2019-05-31
• Study Start: 2019-07-15
• Primary Completion: 2023-06-30
• Study Completion: 2023-06-30
• Status Verified: 2023-12
• Last Update Submitted: 2023-12-04
• Last Update Posted: 2023-12-05

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 84

Inclusion Criteria

• Age 22-36 years
• BMI 18.5 to 34.9
• At least one risk factor for metabolic syndrome based on waist circumference, HDL level or triglyceride level

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Exclusion Criteria

• Tree nut allergy
• Diagnosed chronic disease
• Medication for dyslipidemia or hypertension
• Smoke
• Weight loss medication
• Narcotic medication or illicit drug use
• Pregnancy or lactation or postmenopausal

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Tree Nut Snacks	High Carbohydrate or Tree Nut Food Snacks	Will follow study diet based on the Dietary Guidelines and consume study tree nut snacks between meals.
Carb Snacks	High Carbohydrate or Tree Nut Food Snacks	Will follow study diet based on the Dietary Guidelines and consume study carbohydrate snacks between meals.

Primary Outcome Measures

Name	Time	Method
Waist circumference	18 weeks	Change in waist circumference (in centimeters)
Visceral Fat	18 weeks	Change in quantity of intra-abdominal fat by CT scan

Secondary Outcome Measures

Name	Time	Method
Gene Expression in Adipose Tissue	18 weeks	Change in expression of genes involved in regulation of inflammation and insulin resistance
Glucose	18 weeks	Change in fasting blood glucose (mg/dl)
Inflammation	18 weeks	Change in CRP level (mg/dl)
Dietary Macronutrient Intake	18 weeks	Change in macronutrient composition of the diet
Insulin	18 weeks	Change in serum insulin (mg/dl)

Trial Locations

Locations (1)

Vanderbilt University Medical Center; 🇺🇸 Nashville, Tennessee, United States