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Metabolic and Appetite Responses to a Whey Protein Preload Following Prior Exercise in Overweight Males

Not Applicable
Completed
Conditions
Obesity, Abdominal
Interventions
Other: Mixed macronutrient breakfast meal
Dietary Supplement: Whey protein
Other: Ad libitum lunch meal
Other: Low/moderate intensity exercise
Registration Number
NCT02714309
Lead Sponsor
Northumbria University
Brief Summary

Consuming whey protein may have beneficial effects on health, principally by having an impact on blood glucose metabolism, but also by affecting appetite. The purpose of this project is to investigate the effect of consuming whey protein preload prior to breakfast, following a bout of low/moderate intensity exercise (brisk walking), on glucose and lipids in the blood as well as on appetite.

It is hypothesised that the consumption of whey protein before a meal after prior low/moderate intensity exercise may positively affect postprandial handling as well as appetite sensations and consequently reduce intake at a subsequent meal.

Detailed Description

A crossover design shall be implemented, whereby all participants complete 3 experimental trials in random order, separated by a minimum of 5 days.

Participants will be asked to record their dietary intake for 24 hours before each trial and will be provided with a standardised meal to consume at a set time the previous evening. At each visit participants shall report to the lab at approximately 08.00 hours following a 12 hour fast and having refrained from caffeine, alcohol and vigorous physical activity for 24 hours.

After determination of body mass and stature, a cannula shall be inserted into an antecubital vein in order to collect venous blood samples. A baseline blood sample (10ml) shall be collected, and visual analogue scales (VAS) completed in order to assess appetite sensations.

Following this a 30 minute exercise bout shall be completed in two of the trials, with 30 minutes of seated rest carried out in the control trial. Participants shall walk on a motorised treadmill at a predetermined speed designed to reflect 55% of estimated maximal aerobic capacity. Heart rate and perceived exertion will be sampled every three minutes, while expired air shall be sampled for two minute periods at 5, 15 and 25 minutes.

During the preload trial, participants shall consume a whey protein beverage 15 minutes after completion of the exercise bout. This will consist of 23g whey protein isolate powder (20g protein) combined with 200ml water and 10 drops of energy-free flavouring to create a milkshake-type beverage. In both other trials an isovolumetric bolus of similarly flavoured water shall be consumed. After a further 15 minutes participants shall consume the same mixed-macronutrient breakfast meal under all conditions, and will subsequently rest for a 240 minute period. An ad libitum pasta meal shall be consumed at the end of this period in all trials in order to assess subsequent energy intake. Regular blood samples shall be collected throughout.

Recruitment & Eligibility

Status
COMPLETED
Sex
Male
Target Recruitment
12
Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
Exercise No Preload TrialMixed macronutrient breakfast mealFollowing an exercise bout a mixed macronutrient breakfast meal is consumed without additional protein. An ad libitum lunch meal is subsequently consumed.
Control TrialMixed macronutrient breakfast mealA mixed macronutrient breakfast meal is consumed without additional protein, following a period of rest. An ad libitum lunch meal is subsequently consumed.
Exercise No Preload TrialLow/moderate intensity exerciseFollowing an exercise bout a mixed macronutrient breakfast meal is consumed without additional protein. An ad libitum lunch meal is subsequently consumed.
Exercise No Preload TrialAd libitum lunch mealFollowing an exercise bout a mixed macronutrient breakfast meal is consumed without additional protein. An ad libitum lunch meal is subsequently consumed.
Exercise With Preload TrialWhey proteinFollowing low/moderate intensity exercise bout, whey protein (20g) administered prior to consumption of mixed macronutrient breakfast meal. An ad libitum lunch meal is subsequently consumed.
Exercise With Preload TrialMixed macronutrient breakfast mealFollowing low/moderate intensity exercise bout, whey protein (20g) administered prior to consumption of mixed macronutrient breakfast meal. An ad libitum lunch meal is subsequently consumed.
Exercise With Preload TrialAd libitum lunch mealFollowing low/moderate intensity exercise bout, whey protein (20g) administered prior to consumption of mixed macronutrient breakfast meal. An ad libitum lunch meal is subsequently consumed.
Control TrialAd libitum lunch mealA mixed macronutrient breakfast meal is consumed without additional protein, following a period of rest. An ad libitum lunch meal is subsequently consumed.
Exercise With Preload TrialLow/moderate intensity exerciseFollowing low/moderate intensity exercise bout, whey protein (20g) administered prior to consumption of mixed macronutrient breakfast meal. An ad libitum lunch meal is subsequently consumed.
Primary Outcome Measures
NameTimeMethod
Postprandial blood glucose responses0-240 minutes post breakfast

Blood glucose concentration determined in whole blood sampled at regular intervals post-breakfast

Secondary Outcome Measures
NameTimeMethod
Energy intake at ad libitum lunch meal240 minutes post breakfast breakfast

Energy intake is assessed by recording the mass of food (of known composition) ingested during the lunch meal

Trial Locations

Locations (1)

Faculty of Health and Life Sciences, Northumbria University

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Newcastle upon Tyne, Tyne and Wear, United Kingdom

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