Almond Consumption and Glycemia
Study Details
Study Description
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.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
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 Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Almond Group Participants will consumed almonds every day for 6 months, but will not be allowed to consume any other nuts or nut products. |
Other: Almonds
Participants will consume almonds everyday for 6 months.
|
| Experimental: Control Group Participants will continue with their normal eating routine for 6 months, but will not be allowed to consume any nuts or nut products. |
Other: Control (no nuts)
Participants will not be permited to consume any nuts for 6 months.
|
Outcome Measures
Primary Outcome Measures
- HbA1c [Baseline]
HbA1c.
- fasting glucose [Baseline]
fasting glucose,
- fasting triglycerides [Baseline]
fasting triglycerides
- Change in Body weight [Every two weeks for 6 months.]
Body weight
- Body composition [Baseline]
Body composition
- GLP-1 [Baseline]
GLP-1
- Change in HbA1c [6 months]
HbA1c.
- Change in fasting glucose [6 months]
fasting glucose
- fasting triglycerides [6 months]
fasting triglycerides
- Change in Body composition [6 months]
Body composition
- Change in GLP-1 [6 months]
GLP-1
- fasting insulin [Baseline]
fasting insulin
- total cholesterol [Baseline]
total cholesterol
- LDL-cholesterol [Baseline]
LDL-cholesterol
- HDL-cholesterol [Baseline]
HDL-cholesterol
- GIP [Baseline]
GIP
- change in fasting insulin [6 months]
fasting insulin
- change in total cholesterol [6 months]
total cholesterol
- change in LDL-cholesterol [6 months]
LDL-cholesterol
- change in HDL-cholesterol [6 months]
HDL-cholesterol
- change in GIP [6 months]
GIP
- C-peptide [baseline]
- C-peptide [6 months]
- Homa-IR [baseline]
- Homa-IR [6 months]
- Homa-Percent Beta [Baseline]
- Homa-Percent Beta [6 months]
Secondary Outcome Measures
- 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.
Eligibility Criteria
Criteria
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
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Indiana University School of Medicine | Indianapolis | Indiana | United States | 46202 |
| 2 | Purdue University | West Lafayette | Indiana | United States | 47907 |
| 3 | Purdue University | West Lafayette | Indiana | United States | 47909 |
Sponsors and Collaborators
- Purdue University
- Almond Board of California
Investigators
- Principal Investigator: Richard D Mattes, PhD, Purdue University
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- 055-047