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Completed

NCT Number: NCT03154606

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

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Key information

Conditions

Appetitive Behavior Behavior Behavior, Animal

Age range

20 year–40 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Purdue University

West Lafayette, Indiana, 47907, United States

About this study

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).

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Micellar Casein (#1)

Other

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.

Micellar Casein (#2)

Other

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.

Calcium Caseinate

Other

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.

Sodium Caseinate

Other

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.

Milk Protein Isolate

Other

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.

Pure Protein Blend

Other

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.

Whey Protein Isolate

Other

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.

Native Whey Protein Isolate

Other

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.

Soy Protein

Other

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.

Pea protein

Other

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.

Native Whey: Micellar Casein (50:50) blend

Other

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.

Carbohydrate Control

Other

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.

Primary outcomes

  1. Appetite Sensations of Hunger

    Time frame: 12 testing days across ~6 months

    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.

  2. Appetite Sensations of Fullness

    Time frame: 12 testing days across ~6 months

    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.

  3. Appetite Sensations of Desire to Eat

    Time frame: 12 testing days across ~6 months

    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.

  4. Appetite Sensations of Prospective Food Consumption

    Time frame: 12 testing days across ~6 months

    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.

Secondary outcomes

  1. Perceived Food Cravings: Sweet

    Time frame: 12 testing days across ~6 months

    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.

  2. Perceived Food Cravings: Salty

    Time frame: 12 testing days across ~6 months

    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.

  3. Perceived Food Cravings: Savory-fat

    Time frame: 12 testing days across ~6 months

    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.

  4. Perceived Food Cravings: Meat

    Time frame: 12 testing days across ~6 months

    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.

  5. Perceived Breakfast Palatability

    Time frame: 12 testing days across ~6 months

    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.

  6. Perceived Energy: Sleepiness

    Time frame: 12 testing days across ~6 months

    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.

  7. Perceived Energy: Energy

    Time frame: 12 testing days across ~6 months

    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.

  8. Perceived Energy: Alertness

    Time frame: 12 testing days across ~6 months

    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.

  9. Food Cravings Inventory

    Time frame: 12 testing days across ~6 months

    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.

  10. Hormonal Response to Interventions: Plasma Ghrelin

    Time frame: 12 testing days across ~6 months

    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.

  11. Hormonal Response to Interventions: Plasma PYY

    Time frame: 12 testing days across ~6 months

    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. Hormonal Response to Interventions: Plasma GLP-1

    Time frame: 12 testing days across ~6 months

    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.

  13. 24-h Energy Intake Dietary Recalls

    Time frame: 12 testing days across ~6 months

    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.

  14. Ad Libitum Breakfast

    Time frame: 12 testing days across ~6 months

    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.

Sponsors and collaborators

Lead sponsor

Purdue University

Other

Registry information

Important dates

Study start
2017
Primary completion
2018
Study completion
2018
First posted
May 16, 2017
Registry last updated
May 2, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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