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Completed

NCT Number: NCT02246543

Whey Protein Study - Identification of Sustainable Satiety

This study will have the primary aim to investigate within-day changes in appetite after consumption of high-protein (HP, 30% of calories) and normal, or low, protein (LP, 15% of calories) whey protein meal, in solid and liquid form, on appetite and ad libitum food intake. Secondary objective will be to assess the statistical relationship between plasma concentrations of gut hormones and visual analogue scales (subjective hunger and fullness) and transit time.

In order to investigate the interaction of food structure and protein content on appetite, this requires, in practice, either a differing amount (g) or calorie (kJ) load as a function of energy density (defined as kJ/100g). Delivering the test meal as a solid and liquid form gives an easy solution to achieve this manipulation without compromising the nutritional profile. Following on from this decision, it is easier to produce different preloads using whey protein (rather than meat protein), since it is easily incorporated into test meals.

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Key information

Conditions

Satiety

Age range

20 year–75 year

Sex eligibility

Male

Study type

Interventional

Phase

Not applicable

Primary location

Rowett Institute of Nutrition & Health, University of Aberdeen

Aberdeen, Aberdeen City, AB21 9SB, United Kingdom

About this study

A randomized crossover design in 10 overweight/obese (BMI 26-40) men and 10 lean men (BMI 18.5-25). The control will be water. Each subject will attend the HNU on six separate occasions. The five test meal challenges will involve subjects attending the Human Nutrition Unit (HNU) in the morning, after an overnight fast. The total time of test meal visits will be approximately 4½hours. They will be provided with a standardised meal, after which blood samples will be collected for the first 2hrs. The following five treatments will be tested:

Treatment 1 Control - Water + Egg Yolk Mixture + 13C Octanoic Acid Treatment 2 HPL (High Protein Liquid): 30% protein; 30% fat and 40% carbohydrate (CHO) Treatment 3 LPL (Low Protein Liquid): 15% protein; 30% fat and 55% CHO Treatment 4 HPS (High Protein Solid): 30% protein; 30% fat and 40% CHO Treatment 5 LPS (Low Protein Solid): 15% protein; 30% fat and 55% CHO Test meals will be of fixed nutritional composition for all participants. The liquid meal will be a milk/fruit smoothie mixture and the 'solid' will be in a milk jelly (set) form.

Ad libitum pasta meal: 15% protein; 30% fat and 55% CHO as a homogenous mix and energy density of around 400kJ/100g - served in excess as a individual 600g portion to 'help-yourself'.

Subjective average appetite will be measured (every 30 min by visual analogue scales) over 4hr and ad libitum food intake will measured 4hr after treatment consumption. Ad libitum lunch will be a homogenous pasta meal with tomato sauce and a bottle of water. Blood samples will be collected every 10 min for the first half hour, every 15 min for the second half hour and every 30mins subsequently. The breath gastric emptying measurement will be assessed using the 13Carbon (13C) Octanoic Acid stable isotopic technique19. This involves mixing the tracer into food and taking breath samples and measured by isotope ratio mass spectrometry. 13C Octanoic acid is a medium chain fatty acid which is rapidly absorbed in the duodenum and metabolised in the liver. Following oxidation, the resulting Carbon Dioxide (CO2) is excreted into breath (12 samples will be collected during the 4hr test day).

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

  • BMI = 18.5-40kg/m2

Exclusion criteria

  • Diabetes
  • Severe gastrointestinal disorders
  • Kidney disease
  • Thromboembolic or coagulation disease
  • Hepatic disease
  • Alcohol or any other substance abuse
  • Gout
  • Eating disorders
  • Food allergy
  • Unregulated thyroid disease
  • Psychiatric disorders (including severe depression, lithium treatment, schizophrenia, severe behavioural disorders)
  • Vegetarians & Vegans

Medication Exclusion Criteria:

  • Orlistat (Xenical)
  • Oral antidiabetics, insulin
  • Rimonabant (Acomplia)
  • Digoxin, anti-arrhythmics
  • Sibutramine (Reductil)
  • Tricyclic antidepressants, neuroleptics

Treatment and study plan

Control

Dietary Supplement

Water, Toast & Egg (Yolk only) + 0.1g 13C Octanoic Acid

HPL

Dietary Supplement

High Protein Smoothie (Liquid): 30% protein; 30% fat and 40% CHO + 0.1g 13C Octanoic Acid

LPL

Dietary Supplement

Low Protein Smoothie (Liquid): 15% protein; 30% fat and 55% CHO + 0.1g 13C Octanoic Acid

HPS

Dietary Supplement

High Protein Milk Jelly (Solid): 30% protein; 30% fat and 40% CHO + 0.1g 13C Octanoic Acid

LPS

Dietary Supplement

Low Protein Milk Jelly (Solid): 15% protein; 30% fat and 55% CHO + 0.1g 13C Octanoic Acid

Primary outcomes

  1. Changes in postprandial biomarkers of satiety as measured by gut-related hormones

    Time frame: On each test day blood samples are collected every 10 min for the first half hour, every 15 min for the second half hour and every 30mins subsequently. (Eight samples are therefore collected for 2hours at T0, T10, T20, T30, T45, T60, T90 and T120mins)

    The biomarkers to be measured on the Luminex system are Ghrelin (active), Glucagon-like peptide (GLP1), Peptide YY (PYY), Amylin, Leptin & Insulin

    Biomarkers of Cardiovascular Disease (CVD) risk including total cholesterol, Low Density Lipoprotein Cholesterol (LDL), High Density Lipoprotein (HDL), triglycerides, nonesterified fatty acids (NEFA) will also be measured along with assessment of peripheral glycaemic control, fasting glucose, area under the curve combined with insulin data.

Secondary outcomes

  1. Changes in postprandial gastric emptying, measured using breath samples

    Time frame: On each test day samples are collected every 15mins for the first 2½hrs then every 30mins for the last ½hr. Therefore samples are collected for a total of 3hours at T0, T15, T30, T45, T60, T75, T90, T105, T120, T135, T150 and T180mins.

    This is assessed using the 13C Octanoic Acid stable isotopic technique. A tracer is mixed into food and breath samples are collected which are analysed by isotope ratio mass spectrometry. 13C Octanoic acid is a medium chain fatty acid which is rapidly absorbed in the duodenum and metabolised in the liver. Following oxidation, the resulting CO2 is excreted into breath (12 samples will be collected during the 4hr test day).

Other outcomes

  1. Changes in subjective appetite using visual analogue scales

    Time frame: On each test day the appetite questions are answered every 30mins during the 4hour visit.

    Every 30mins, six appetite questions are answered

    • How hungry do you feel?
    • How full do you feel?
    • How strong is your desire to eat?
    • How much do you think you could eat now
    • How thirsty are you?
    • Preoccupation with thoughts of food?

  2. Ad libitum food intake

    Time frame: Recorded at T240mins on the test day visit and then for approximately 12hours at home. Therefore all food consumed during the 24hours of the test day will be assessed

    To assess if each test breakfast provided has an influence on subsequent meals the consumption of the following are recorded:

    • Ad libitum pasta meal: 15% protein; 30% fat and 55% CHO as a homogenous mix and energy density of around 400kJ/100g - served in excess at lunchtime as an individual 600g portion to 'help-yourself'.

    Participants then record all additional meals & snacks consumed at home in a food diary

Sponsors and collaborators

Lead sponsor

University of Aberdeen

Other

Registry information

Important dates

Study start
2013
Primary completion
2015
Study completion
2015
First posted
Sep 22, 2014
Registry last updated
Mar 24, 2016

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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