Metabolic and Appetite Responses to a Whey Protein Preload Following Prior Exercise in Overweight Males
Condition: Obesity, Abdominal
MeSH terms: Overweight; Obesity, Abdominal
Study type: Interventional

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.
    

Intervention name(s): Whey protein; Mixed macronutrient breakfast meal; Ad libitum lunch meal; Low/moderate intensity exercise
Intervention type(s): Dietary Supplement; Other; Other; Other
Intervention description(s): 20 g whey protein isolate (Arla Foods Ingredients Group) added to 200ml water and served as a beverage; A standardised mixed-macronutrient breakfast served to all participants. The macronutrient distribution of the breakfast is 13% protein, 70% carbohydrate, 17% fat (1958 kilojoules (kJ); 468 kcal total); A mixed-macronutrient lunch served to all participants ad libitum. The macronutrient distribution of the lunch is 14% protein, 51% carbohydrate, 35% fat; A 30 minute bout of treadmill walking is performed on a motorised treadmill at a low/moderate intensity (55% estimated VO2max)
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Participant)
Primary purpose: Basic Science
Keywords: Postprandial glycemia; Metabolic health measures