Effects of Consuming Protein Shakes, Varying in Protein Source, on Appetite, Satiety and Energy Intake
Condition: Obesity
Study type: Interventional

Summary: 
      Background: Consistent data from acute, single preload studies demonstrate improvements in
      perceived appetite and satiety following the consumption of high-protein preloads compared to
      normal protein preloads. However, it is currently unclear as to whether protein quality
      (i.e., protein source) or the use of appetite questionnaires influences these outcomes.
      Objective: To examine whether the consumption of protein preloads (egg white isolate, whey
      isolate, micellar casein, and instant egg white) differentially modulate postprandial hunger,
      fullness, desire to eat, prospective food consumption, eating initiation, and subsequent food
      intake; and if the use of appetite questionnaires to assess perceived appetite and satiety
      affect subsequent energy intake. Methods: Twelve young adults (age: 22±1 y; BMI: 22.1±0.9
      kg/m2) reported to the research facility between 7 - 9 am to complete each 4-h testing day. A
      set of questionnaires assessing perceived hunger, fullness, desire to eat, prospective food
      consumption were completed followed by the consumption of the 130 kcal beverage preloads,
      varying in protein source. A water preload was also included as a control. The same set of
      questionnaires along with the assessment of whether they would like to eat again were
      completed every 30 min throughout the 4-h postprandial period. On a separate day, all twelve
      young adults also completed a similar testing day except were not given questionnaires
      throughout the 4-h postprandial period. After the 4-h, the participants were given an ad
      libitum pasta meal to consume until 'comfortably full.' Results: The consumption of the
      protein preloads improved hunger, fullness, desire to eat, prospective food consumption and
      delayed the request to eat again vs. the control (water); however, no differences in appetite
      and satiety outcomes were observed between protein sources. No differences in energy content
      at the lunch meal were observed between any preloads. The use of questionnaires did not
      change energy consumed at the lunch meal. Conclusions: When comparing high-quality
      animal-based proteins consumed as a beverage preload, relatively no differences in markers of
      appetite control and satiety were detected, suggesting that protein quality has little impact
      on these outcomes when consuming 30g of protein. In addition, the use of questionnaires
      assessing perceived appetite and satiety do not impact subsequent energy intake.
    

Detailed description: 
      the following acute, randomized crossover study will be completed in 12 healthy adults (age
      18-35y; BMI: 18-29.9 kg/m2) to compare 135 kcal protein beverages consumed at breakfast
      containing 30 g of protein from whey isolate (WY), casein (CS), egg white isolate (EWI), egg
      white protein concentrate (EWP), or a 0 kcal water beverage - which serves as the control
      (CON). Note: the W beverage will be consumed on 2 different days; these days only differ by
      the postprandial outcomes completed (see below).

      The participants will report to the research facility between 7 - 9 am to complete each 4-h
      testing day. Prior to testing, the participants will be provided with a standardized dinner
      to consume, at home, between 5-7 pm the night before each 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 will be completed. At time 0 min, one
      of the breakfast beverages will be provided. Immediately following the first swallow of the
      breakfast shakes, the participants will be given a questionnaire assessing the palatability
      of each shake. The participants will consume the beverage within 20 min. For 5 of the 6 days,
      a set of questionnaires will be completed every 30 min throughout the 4-h postprandial
      period. For one of the W days, no questionnaires will be completed. After the 4-h, the
      participants will be given an ad libitum pasta meal to assess energy intake. 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 following the consumption of the previous day's breakfast beverage.
    

Intervention name(s): Water Preload Drink; Whey Protein Isolate Drink; Micellar Casein Protein Drink; Egg White Isolate Protein Drink; Egg White Concentrate Protein Drink
Intervention type(s): Dietary Supplement; Dietary Supplement; Dietary Supplement; Dietary Supplement; Dietary Supplement
Intervention description(s): Participants were given 275 ml (0 kcal) water to consume in the morning following an overnight fast. This served as the control drink.; Participants were given an isovolumetric (to the water), 160 kcal drink with 30 g whey protein to consume in the morning following an overnight fast.; Participants were given an isovolumetric (to the water), 160 kcal drink with 30 g micellar casein to consume in the morning following an overnight fast.; Participants were given an isovolumetric (to the water), 160 kcal drink with 30 g egg white isolate protein to consume in the morning following an overnight fast.; Participants were given an isovolumetric (to the water), 160 kcal drink with 30 g egg white concentrate protein to consume in the morning following an overnight fast.
Intervention MeSH terms: Caseins
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Prevention