The Effects of Protein Source on Appetite Control, Satiety, and Subsequent Food Intake

The investigators propose a randomized, tightly-controlled breakfast trial in normal to overweight adults that will test whether the consumption of various types of protein-rich meals, containing ~24g of protein, will differentially alter food intake and meal initiation through proposed appetite and satiety mechanisms.

Aim 1: To examine whether the consumption of protein-rich meals that vary in protein quality (source) effect:

1. postprandial feelings of hunger, fullness, desire to eat, prospective food consumption
2. postprandial fluctuations in key appetite and satiety hormones
3. eating initiation (i.e., motivation to eat (again))
4. food cravings

Aim 2: To examine whether the consumption of protein-rich meals that vary in protein quality (source) effect:

1. energy intake and food choice within the breakfast meal
2. energy intake and food choice at the next eating occasion
3. energy intake and food choice across the entire day

Study Overview

• Status: Completed
• Conditions: Appetitive Behavior
• Intervention / Treatment: Other: Micellar Casein (#1); Other: Micellar Casein (#2); Other: Calcium Caseinate; Other: Sodium Caseinate; Other: Milk Protein Isolate; Other: Pure Protein Blend; Other: Whey Protein Isolate; Other: Native Whey Protein Isolate; Other: Soy Protein; Other: Pea Protein; Other: Native Whey: Micellar Casein (50:50) blend; Other: Carbohydrate Control

Detailed Description

Experimental Design: For 3 consecutive days/pattern, the participants will consume the respective treatment, at home, between 7-9 am and refrain from eating or drinking anything other than water until 12:00pm. On day 3, the participants will consume a standardized dinner at home the night before testing. On day 4, the participants will report to the research facility between 6-8 am to complete each 5-h testing day. Upon arrival to the facility, each participant will become familiarized with the testing day procedures. At time -15 min, a baseline set of computerized questionnaires (and/or blood samples) will be completed. At time +0 min, the respective breakfast treatment will be provided. Immediately following the first swallow of the breakfast meal, the participants will be given a questionnaire assessing the palatability. The participants will consume the breakfast within 20 min. After breakfast, the participants will continue to complete the questionnaires (and/or blood samples) every 30 min throughout the 5-h postprandial period. Throughout the day, the participants will also indicate if/when they would like to eat again. Regardless of the participants' meal timing request, at +240min post-breakfast, the participants will be provided with an ad libitum lunch. For the lunch meal, the participants will be given 30 min to "consume as much or as little as possible until comfortably full." Following these procedures, the participants will be allowed to leave the facility. The next day, a dietary recall will be performed to assess daily energy intake across the previous day. Lastly, on day 5 (at home), the participants will be provided with their respective breakfast along with additional carbohydrate and/or fat foods. Once the treatment breakfast is consumed, the participants can select and consume as much of the additional foods as they wish to consume within the breakfast time period (30 minutes).

• Study Type: Interventional
• Enrollment (Actual): 35
• Phase: Not Applicable

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 40 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Males and females
• All ethnicities
• Age: 20-40y
• BMI/BMI Percentile: 18.5-29.9 kg/m2
• Consumes breakfast (>110 kcal prior to 10 am) at least 5 days/week for the past year
• Never smoked or used other tobacco products
• Willing to consume the study breakfasts
• Generally healthy (as assessed by Medical History Questionnaire)
• Health conscious as determined by answering yes to 3 pre-screening health & lifestyle questions
• Rating of ≥ 5 illustrating a minimum of "neither like nor dislike on a hedonic 9 pt taste test of all testing treatments

Exclusion Criteria:

• Clinically diagnosed with an eating disorder
• Metabolic, hormonal, and/or neural conditions/diseases that influence metabolism or appetite
• Currently or previously on a weight loss or other special diet (in the past 6 months)
• Gained/lost ≥4.5kg over the past 6 months
• Donated (or plan to donate) blood through the American Red Cross within the past 6 months (or future 6 months)
• Taking medication that would directly influence appetite (weight-loss drugs or antidepressant, steroid, or thyroid medication, unless dosage has been stable for at least 6 months)
• Not willing or able to complete all study testing procedures
• Clinically diagnosed with a sleeping disorder

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: HP-Beverage Breakfast; The study participants will be provided with breakfast meals to consume. The energy content of the breakfast meals will be standardized to ~250 kcal. The meals will include the same fat content but will vary in protein source. All ingredients are GRAS listed and approved. All participants will complete all 12 interventions.	Other: Micellar Casein (#1); The study participants will be provided with breakfast meals to consume. The energy content of the breakfast meals will be standardized to ~250 kcal. The meals will include the same fat content but will contain protein sourced predominantly from micellar casein. All ingredients are GRAS listed and approved.; Other: Micellar Casein (#2); The study participants will be provided with breakfast meals to consume. The energy content of the breakfast meals will be standardized to ~250 kcal. The meals will include the same fat content but will contain protein sourced predominantly from micellar casein. All ingredients are GRAS listed and approved.; Other: Calcium Caseinate; The study participants will be provided with breakfast meals to consume. The energy content of the breakfast meals will be standardized to ~250 kcal. The meals will include the same fat content but will contain protein sourced predominantly from calcium casein. All ingredients are GRAS listed and approved.; Other: Sodium Caseinate; The study participants will be provided with breakfast meals to consume. The energy content of the breakfast meals will be standardized to ~250 kcal. The meals will include the same fat content but will contain protein sourced predominantly from sodium caseinate. All ingredients are GRAS listed and approved.; Other: Milk Protein Isolate; The study participants will be provided with breakfast meals to consume. The energy content of the breakfast meals will be standardized to ~250 kcal. The meals will include the same fat content but will contain protein sourced predominantly from milk protein caseinate. All ingredients are GRAS listed and approved.; Other: Pure Protein Blend; The study participants will be provided with breakfast meals to consume. The energy content of the breakfast meals will be standardized to ~250 kcal. The meals will include the same fat content but will contain protein sourced predominantly from pure protein blend. All ingredients are GRAS listed and approved.; Other: Whey Protein Isolate; The study participants will be provided with breakfast meals to consume. The energy content of the breakfast meals will be standardized to ~250 kcal. The meals will include the same fat content but will contain protein sourced predominantly from whey protein blend. All ingredients are GRAS listed and approved.; Other: Native Whey Protein Isolate; The study participants will be provided with breakfast meals to consume. The energy content of the breakfast meals will be standardized to ~250 kcal. The meals will include the same fat content but will contain protein sourced predominantly from Native Whey Protein Isolate. All ingredients are GRAS listed and approved.; Other: Soy Protein; The study participants will be provided with breakfast meals to consume. The energy content of the breakfast meals will be standardized to ~250 kcal. The meals will include the same fat content but will contain protein sourced predominantly from soy protein. All ingredients are GRAS listed and approved.; Other: Pea Protein; The study participants will be provided with breakfast meals to consume. The energy content of the breakfast meals will be standardized to ~250 kcal. The meals will include the same fat content but will contain protein sourced predominantly from pea protein. All ingredients are GRAS listed and approved.; Other: Native Whey: Micellar Casein (50:50) blend; The study participants will be provided with breakfast meals to consume. The energy content of the breakfast meals will be standardized to ~250 kcal. The meals will include the same fat content but will contain protein sourced predominantly from native whey: micellar casein (50:50) blend. All ingredients are GRAS listed and approved.
Active Comparator: Carbohydrate Control; The study participants will be provided with breakfast meals to consume. The energy content of the breakfast meals will be standardized to ~250 kcal. The meals will include the same fat content but will primarily as carbohydrates as a control. All ingredients are GRAS listed and approved. All participants will complete all 12 interventions.	Other: Carbohydrate Control; The study participants will be provided with breakfast meals to consume. The energy content of the breakfast meals will be standardized to ~250 kcal. The meals will include the same fat content but will contain predominantly carbohydrates as a control. All ingredients are GRAS listed and approved.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Appetite Sensations of Hunger	Questionnaires assessing the appetitive sensations of hunger will be completed at specific times throughout each of the the 4-h testing days. The questionnaires contain VAS incorporating a horizontal line rating scale for each response. The questions are worded as "how strong is your feeling of" with anchors of "not all" to "extremely." A summation (area under the curve) will be calculated.	12 testing days across ~6 months
Appetite Sensations of Fullness	Questionnaires assessing the appetitive sensations of fullness will be completed at specific times throughout each of the 4-h testing days. The questionnaires contain VAS incorporating a horizontal line rating scale for each response. The questions are worded as "how strong is your feeling of" with anchors of "not all" to "extremely." A summation (area under the curve) will be calculated.	12 testing days across ~6 months
Appetite Sensations of Desire to Eat	Questionnaires assessing the appetitive sensations of desire to eat will be completed at specific times throughout each of the the 4-h testing days. The questionnaires contain VAS incorporating a horizontal line rating scale for each response. The questions are worded as "how strong is your feeling of" with anchors of "not all" to "extremely." A summation (area under the curve) will be calculated.	12 testing days across ~6 months
Appetite Sensations of Prospective Food Consumption	Questionnaires assessing the appetitive sensations of prospective food consumption will be completed at specific times throughout each of the the 4-h testing days. The questionnaires contain VAS incorporating a horizontal line rating scale for each response. The questions are worded as "how strong is your feeling of" with anchors of "not all" to "extremely." A summation (area under the curve) will be calculated.	12 testing days across ~6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Perceived Food Cravings: Sweet	Questionnaires assessing the food cravings will be completed at specific times throughout each of the 4-h testing days. The questionnaires contain VAS incorporating a horizontal line rating scale for each response. The questions are worded as "how strong is your feeling of" with anchors of "not all" to "extremely." A summation (area under the curve) will be calculated.	12 testing days across ~6 months
Perceived Food Cravings: Salty	Questionnaires assessing the food cravings will be completed at specific times throughout each of the the 4-h testing days. The questionnaires contain VAS incorporating a horizontal line rating scale for each response. The questions are worded as "how strong is your feeling of" with anchors of "not all" to "extremely." A summation (area under the curve) will be calculated.	12 testing days across ~6 months
Perceived Food Cravings: Savory-fat	Questionnaires assessing the food cravings will be completed at specific times throughout each of the 4-h testing days. The questionnaires contain VAS incorporating a horizontal line rating scale for each response. The questions are worded as "how strong is your feeling of" with anchors of "not all" to "extremely." A summation (area under the curve) will be calculated.	12 testing days across ~6 months
Perceived Food Cravings: Meat	Questionnaires assessing the food cravings will be completed at specific times throughout the each of the 4-h testing days. The questionnaires contain VAS incorporating a horizontal line rating scale for each response. The questions are worded as "how strong is your feeling of" with anchors of "not all" to "extremely." A summation (area under the curve) will be calculated.	12 testing days across ~6 months
Perceived Breakfast Palatability	Questionnaires assessing the breakfast palatability will be completed at specific times throughout each of the 4-h testing days. The questionnaires contain VAS incorporating a horizontal line rating scale for each response. The questions are worded as "how strong is your feeling of" with anchors of "not all" to "extremely." A summation (area under the curve) will be calculated.	12 testing days across ~6 months
Perceived Energy: Sleepiness	Questionnaires assessing perceived sleepiness will be completed at specific times throughout each of the 4-h testing days. The questionnaires contain VAS incorporating a horizontal line rating scale for each response. The questions are worded as "how strong is your feeling of" with anchors of "not all" to "extremely." A summation (area under the curve) will be calculated.	12 testing days across ~6 months
Perceived Energy: Energy	Questionnaires assessing perceived energy will be completed at specific times throughout each of the 4-h testing days. The questionnaires contain VAS incorporating a horizontal line rating scale for each response. The questions are worded as "how strong is your feeling of" with anchors of "not all" to "extremely." A summation (area under the curve) will be calculated.	12 testing days across ~6 months
Perceived Energy: Alertness	Questionnaires assessing perceived alertness will be completed at specific times throughout each of the 4-h testing days. The questionnaires contain VAS incorporating a horizontal line rating scale for each response. The questions are worded as "how strong is your feeling of" with anchors of "not all" to "extremely." A summation (area under the curve) will be calculated.	12 testing days across ~6 months
Food Cravings Inventory	Participants will fill out a Food Cravings Inventory (FCI) at 4-h post-breakfast on each testing day. The FCI is a reliable and valid self-report measure of general and specific food cravings including cravings for high fat foods, carbohydrates/starches, sweets, and fast food. The FCI defines a craving as an intense desire to consume a particular food (or food type) that is difficult to resist.	12 testing days across ~6 months
Hormonal Response to Interventions: Plasma Ghrelin	Ten blood samples (4 ml/sample) will be collected throughout each of the the 4-h testing days. The samples will be collected in EDTA test tubes containing pefabloc SC and DPP-IV to reduce protein degradation. Within 10-min of collection, the samples will be centrifuged, and the plasma will be stored at -80°C for future analysis.	12 testing days across ~6 months
Hormonal Response to Interventions: Plasma PYY	Ten blood samples (4 ml/sample) will be collected throughout each of the 4-h testing days. The samples will be collected in EDTA test tubes containing pefabloc SC and DPP-IV to reduce protein degradation. Within 10-min of collection, the samples will be centrifuged, and the plasma will be stored at -80°C for future analysis.	12 testing days across ~6 months
Hormonal Response to Interventions: Plasma GLP-1	Ten blood samples (4 ml/sample) will be collected throughout each of the the 4-h testing days. The samples will be collected in EDTA test tubes containing pefabloc SC and DPP-IV to reduce protein degradation. Within 10-min of collection, the samples will be centrifuged, and the plasma will be stored at -80°C for future analysis.	12 testing days across ~6 months
24-h Energy Intake Dietary Recalls	To assess the participant's total energy content, macronutrient content, macronutrient consumption, and meal patterning, all subjects will complete a dietary recall following each testing day. The study staff will contact the participant the day after each of the testing days and ask questions related to the quantity, type, brand, preparation, and timing of food consumed following the testing day. Total energy content and macronutrient composition will be calculated using nutrition software.	12 testing days across ~6 months
Ad Libitum Breakfast	Free-living energy intake at breakfast will be assessed on day 5, of each testing period, through a meal-specific food packout . The participants will first consume the respective breakfast treatment. Additionally, the participants will be provided with an excess of macronutrient-specific foods to consume, ad libitum for the breakfast time period (30 minutes), after the required, respective breakfast treatment. All food items will be initially weighed and recorded. The participants will be instructed to return all uneaten foods as well as all wrappers and containers from consumed food. Any partially eaten, returned items will be weighed accordingly. Breakfast meal energy and macronutrient content will be assessed from these packouts.	12 testing days across ~6 months

Collaborators and Investigators

• Sponsor: Purdue University
• Investigators: Principal Investigator: Heather J Leidy, PhD, Purdue University

Publications and helpful links

General Publications

• Douglas SM, Leidy HJ. Novel Methodological Considerations Regarding the Use of Visual Analog Scale (VAS) Appetite Questionnaires in Tightly Controlled Feeding Trials. Curr Dev Nutr. 2019 May 2;3(6):nzz061. doi: 10.1093/cdn/nzz061. eCollection 2019 Jun.

Study record dates

Study Major Dates

• Study Start (Actual): March 21, 2017
• Primary Completion (Actual): July 27, 2018
• Study Completion (Actual): July 27, 2018

Study Registration Dates

• First Submitted: April 19, 2017
• First Submitted That Met QC Criteria: May 12, 2017
• First Posted (Actual): May 16, 2017

Study Record Updates

• Last Update Posted (Actual): May 2, 2019
• Last Update Submitted That Met QC Criteria: April 30, 2019
• Last Verified: April 1, 2019

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Calcium-Regulating Hormones and Agents; Chelating Agents; Sequestering Agents; Calcium; Caseins
• Other Study ID Numbers: 1701018659

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No