Metabolic Effects of Almond in the Longer-term Study (MEAL)

May 28, 2013 updated by: Richard Mattes, Purdue University

Effects of Chronic Almond Consumption at Meals or as Snacks on Appetite, Intake, Body Weight, Glycemia, Insulinemia and Lipids in Healthy Adults.

Identifying snacks that do not contribute to positive energy balance is crucial in weight management. The satiating effects of almonds, coupled with their convenience and palatability make them a promising weight management aid. Therefore, this study aimed to examine the effects of almond consumption with meals versus snacks on outcomes such as appetite, energy intake, body weight, as well as blood glucose, insulin and lipid responses.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Experiment protocol and measurements

i) Oral glucose tolerance test (OGTT) sessions

At baseline, participants attended a session where a standard OGTT with drinks containing 75 grams dextrose was performed following an overnight fasting. Serum glucose and insulin concentrations were measured at 0 and 120 minutes of the session. During the same session, height, weight (Tanita), body fat (air displacement plethysmography, BOD POD), waist circumference, and blood pressure were measured. Participants also completed a 24-hour dietary recall using a multi-pass interview method and standard questionnaires that assessed personality, eating behavior and habitual physical activity levels during the OGTT session. After the completion of this session, participants were asked to record their hourly appetite sensations, measured as "hunger", "fullness" and "desire to eat" on visual analog scales, during waking hours for a day before attending the next (clinical) visit. Participants repeated this session after four weeks of almond consumption.

ii) Acute feeding sessions

Within a week following the OGTT session, participants returned for an acute-feeding session, after an overnight fasting of at least 10 hours. This session began between 7:00 am and 8:00 am, and lasted for approximately 515 minutes. Upon arrival, an indwelling arm catheter was placed in the upper arm for blood sample collection. Participants rested for 15 minutes after catheter placement, before a baseline blood sample was drawn. Immediately after the first blood sample collection, a standard breakfast was served, and participants were instructed to consume the entire portion within 10 minutes. Subsequent blood samplings were performed at 15, 45, 60, 90, 120, 180, and 240 minutes after the breakfast, before a standard lunch was provided to the participants. Again, participants were given 10 minutes to consume the lunch, before blood samples were taken at similar intervals again (at 265, 295, 310, 340, 370, 430, and 490 minutes of the session). Participants randomized into the BF and LN groups received 43 grams of almonds together with their meals, while the MS and AS groups consumed 43 grams of almonds 120 minutes after breakfast and lunch respectively. Participants also recorded their "hunger", "fullness", and "desire to eat" sensations when blood samples were taken. During the acute-feeding session, activities that may alter appetite sensations (e.g. sleeping and watching movies containing food cues) were prohibited. Postprandial glucose, insulin and triacylglycerol concentrations were measured for all 15 samples collected from each participant. Participants in all almond groups group were also asked to rate their likings for the almonds they ingested using a general label magnitude scale, and their action responses to almonds using the "food action rating scale", a visual analog scale ranging from "I would eat the almonds only if I were forced to" to "I would eat this food every opportunity I had" anchored to the 2 extremes. This session was repeated again after four weeks of almond supplementation.

iii) Weekly follow-ups

Following the baseline acute-feeding session, participants were asked to consume 43 grams of almonds every day at times based on their group randomization. The CL group was instructed to avoid all nuts and seeds in the diet during the study period. All almonds were dry-roasted and lightly salted, and were pre-weighed and per-packaged for convenience. Except for the permission to adjust dietary intake due to almond supplement, participants were asked to maintain their dietary intakes and physical activity levels. A ruse (breath analysis) was introduced in order to enhance the compliance of participants to consuming almonds at the designated times of day. Compliance to almond consumption was assessed through fasting plasma α-tocopherol. Participants attended weekly visit (week-1, 2 and 3) after an overnight fasting, during which body weight was recorded and compliance to study protocol reinforced. During the week-2 visit, participants were also asked to complete a 24-hour dietary intake assessment using the multi-pass interview method and appetite sensation ratings on VAS at every waking hour for a day. On week-4, participants returned for OGTT and acute-feeding sessions as described above. The study protocol was approved by the Purdue University Institutional Review Board.

Study Type

Interventional

Enrollment (Actual)

150

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Indiana
      • West Lafayette, Indiana, United States, 47907
        • Purdue University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 60 years (ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Not taking any medication known to affect glycemia, lipid metabolism or appetite
  • Regular breakfast consumers
  • Eat at least 5 meals a day
  • Weight stable
  • Either one of the 6 conditions
  • BMI 27-35
  • Family history of diabetes
  • Fasting glucose between 6.1-6.9 mmol/L
  • 2-hour glucose 7.8-11.1 mmol/L
  • blood pressure >130/85 mmHg
  • Waist >102cm (men) and >88cm (women)

Exclusion Criteria:

  • Nut allergy
  • Not willing to eat test foods and almonds

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: PREVENTION
  • Allocation: RANDOMIZED
  • Interventional Model: PARALLEL
  • Masking: NONE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
EXPERIMENTAL: Breakfast
Almonds (43g/day) were consumed with breakfast for four weeks.
43 grams of almonds were supplemented to the 4 intervention arms but eaten at different times of day (with meals or alone as snacks) for 4 weeks. Control group was asked to avoid all nuts/seeds during the study period
EXPERIMENTAL: Morning snack
Almonds (43g/day) were consumed alone as morning snacks for four weeks.
43 grams of almonds were supplemented to the 4 intervention arms but eaten at different times of day (with meals or alone as snacks) for 4 weeks. Control group was asked to avoid all nuts/seeds during the study period
EXPERIMENTAL: Lunch
Almonds (43g/day) were consumed with lunch for four weeks.
43 grams of almonds were supplemented to the 4 intervention arms but eaten at different times of day (with meals or alone as snacks) for 4 weeks. Control group was asked to avoid all nuts/seeds during the study period
EXPERIMENTAL: Afternoon snack
Almonds (43g/day) were consumed alone as afternoon snacks for four weeks.
43 grams of almonds were supplemented to the 4 intervention arms but eaten at different times of day (with meals or alone as snacks) for 4 weeks. Control group was asked to avoid all nuts/seeds during the study period
NO_INTERVENTION: Control no nuts
Avoided all nuts and seeds

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postprandial glucose, insulin and lipids
Time Frame: 490 minutes
Responses of these parameters to a standard breakfast and a standard lunch for all participants, plus almonds at designated times according to group randomization.
490 minutes
Anthropometric measurements
Time Frame: 4 weeks
Changes in body weight, BMI, fat mass, waist circumference over 4 weeks
4 weeks
Fasting blood biochemistries
Time Frame: 4 weeks
Fasting glucose, insulin and lipids at baseline, week-1, 2, 3 and 4
4 weeks
Dietary intake
Time Frame: 4 weeks
Dietary intakes were assessed at baseline, week-2, and week-4 of study
4 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Blood pressure
Time Frame: Baseline and week-4
Blood pressure measurements at baseline and final week of study
Baseline and week-4
Appetite ratings
Time Frame: Baseline, week-2, and week-4
Baseline, week-2, and week-4
Postprandial appetite sensations
Time Frame: 490 minutes
490 minutes

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

October 1, 2010

Primary Completion (ACTUAL)

June 1, 2012

Study Completion (ACTUAL)

June 1, 2012

Study Registration Dates

First Submitted

September 12, 2012

First Submitted That Met QC Criteria

September 19, 2012

First Posted (ESTIMATE)

September 24, 2012

Study Record Updates

Last Update Posted (ESTIMATE)

May 30, 2013

Last Update Submitted That Met QC Criteria

May 28, 2013

Last Verified

May 1, 2013

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 055-022
  • Snacking study (OTHER_GRANT: Almond Board of California)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Obesity

Clinical Trials on Almonds 43g/day

3
Subscribe