Almond Consumption and Glycemia

Not Applicable

Completed

• Conditions: Glucose Intolerance; Glucose Metabolism Disorders (Including Diabetes Mellitus); Lipid Metabolism Disorder; Appetite Disorders
• Interventions: Other: Control (no nuts); Other: Almonds

• Registration Number: NCT03236116
• Lead Sponsor: Purdue University

Brief Summary

This study will examine the effects of almonds consumed by adults with different body fat distributions on indices of carbohydrate and lipid metabolism.

Detailed Description

There is considerable evidence supporting a causal role for truncal visceral fat depots in glucose dysregulation. Individuals with large visceral fat depots have impaired suppression of free fatty acid release in response to insulin, elevated triglycerides and low concentrations of high density lipoprotein cholesterol. The high free fatty acid concentration may induce insulin resistance in the muscle and liver. There is more recent evidence that truncal subcutaneous fat depots are also problematic, though this literature is mixed. In contrast, gluteo-femoral fat depots have not been implicated in insulin resistance and dysregulation of carbohydrate metabolism. Failure to account for differences in the contributions of these depots will add noise to measurements of dietary interventions to mitigate glucose dysregulation. Previous studies have reported evidence indicating acute and chronic consumption of almonds improves glycemia. Acute effects are important indicators of health benefit, but longer-term trials, ones permitting identification of the effects of a dietary intervention on HbA1c, are more telling and clinically relevant. To more definitively establish the association between almond consumption and improved carbohydrate metabolism, we propose a six-month trial that contrasts the effects of almond consumption at optimal times of the day versus consumption of low nutrient dense snack foods on indices of carbohydrate metabolism, food intake and appetite in adults characterized by three distinct fat depots.

Participants will consume either almonds, or no nuts every day for 6 months. At baseline, participants will be weighed and undergo a DEXA scan to determine body fat composition and will be assigned a group. Blood will also be collected fasted and at stipulated times in response to a meal tolerance test to measure insulin, glucose, C-peptide, HbA1c, lipid panel, gut peptides, and compliance to the diet. Participants will be given links to complete appetite ratings and record food intake. Participants will report to the lab every two weeks to be weighed, and get a resupply of almonds (if in the almond group). At the two-week mark on months 2 and 4, participants will be weighed, blood will be taken to assess compliance to the diet, and links will be given to complete appetite ratings and record food intake. At month 6, all measurements from baseline will be repeated.

Study Timeline

• Study First Submitted: 2017-07-13
• Study First Submitted QC: 2017-07-28
• Study Start: 2017-08-01
• Study First Posted: 2017-08-01
• Primary Completion: 2020-03-20
• Study Completion: 2020-12-31
• Status Verified: 2021-01
• Last Update Submitted: 2021-01-06
• Last Update Posted: 2021-01-07

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 75

Inclusion Criteria

• Meeting one of the following body fat distribution criteria determined by DEXA: 1. High visceral fat 2. High gluteo-femoral fat 3. High truncal subcutaneous fat
• 18-60 years
• no nut allergies

Exclusion Criteria

• Not meeting one of the body fat distribution criteria
• allergic to nuts

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Control Group	Control (no nuts)	Participants will continue with their normal eating routine for 6 months, but will not be allowed to consume any nuts or nut products.
Almond Group	Almonds	Participants will consumed almonds every day for 6 months, but will not be allowed to consume any other nuts or nut products.

Primary Outcome Measures

Name	Time	Method
HbA1c	Baseline	HbA1c.
fasting insulin	Baseline	fasting insulin
change in GIP	6 months	GIP
Change in HbA1c	6 months	HbA1c.
change in fasting insulin	6 months	fasting insulin
GIP	Baseline	GIP
change in LDL-cholesterol	6 months	LDL-cholesterol
fasting glucose	Baseline	fasting glucose,
GLP-1	Baseline	GLP-1
Change in fasting glucose	6 months	fasting glucose
total cholesterol	Baseline	total cholesterol
Change in GLP-1	6 months	GLP-1
Body composition	Baseline	Body composition
C-peptide	6 months
Homa-IR	6 months
fasting triglycerides	6 months	fasting triglycerides
Change in Body weight	Every two weeks for 6 months.	Body weight
LDL-cholesterol	Baseline	LDL-cholesterol
Homa-Percent Beta	6 months
Change in Body composition	6 months	Body composition
HDL-cholesterol	Baseline	HDL-cholesterol
change in total cholesterol	6 months	total cholesterol
change in HDL-cholesterol	6 months	HDL-cholesterol

Secondary Outcome Measures

Name	Time	Method
Diet Quality	Three days (two non-consecutive week days and one weekend day) at baseline, month 2, 4, and 6.	Determine the effect of substituting a wholesome snack food (almonds) for more traditional, less nutrient dense, snack foods on total diet quality. Food intake will be measured by the ASA-24 for three days (two non-consecutive week days and one weekend day) at baseline, month 2, 4, and 6.
Compliance	Baseline, month 2, 4, and 6.	Demonstrate the utility of a novel, sensitive approach to document compliance with a prescription to ingest almonds on a daily basis for six months.

Trial Locations

Locations (2)

Purdue University; 🇺🇸 West Lafayette, Indiana, United States

Indiana University School of Medicine; 🇺🇸 Indianapolis, Indiana, United States