Impact of Single Exercise Session Conducted Prior to PKU Type Meal on Appetite Hormones and Energy Intake
Condition: Healthy
Study type: Interventional

Summary: 
      The study applied a randomized, crossover design with preliminary (screening) session and two
      sequenced experimental trials. Trials were marked as Control trial and Exercise trial.
      Participants were asked to either resting (Control trial) or exercising (Exercise trial) for
      one hour. In the two trials, appetite questionnaires were obtained, blood samples were
      collected, and metabolic rates were measured every 30 minutes. Participants in both trials
      were presented to a standard isocaloric PKU type meal at 120 min. After the completion of the
      last measurement, the participants were presented with an ad libitum buffet test meal at 300
      min. Participants required to record their EI for the remainder of the experimental day using
      a self-recorded food diary. Two days prior the experimental trials participants refrained
      from exercise and alcohol intake. All data collection took place in the metabolic research
      unit at New Lister Building, Glasgow Royal Infirmary.
    

Detailed description: 
      Participants of the study were essentially healthy men with body mass index (BMI) ≤29 kg/m2
      and aged between 22-35 years, recruited by advertisements and word of mouth. Study
      participants were required to be non-smokers, to have stable body weight for one month prior
      to study enrolment, and were not taking any medication, nutritional supplement or being on a
      special diet. Exclusion criteria included chronic illness, eating disorder and history of
      gastrointestinal operations which could interfere with the results of the study. Written
      informed consent were obtained prior commencing the study. The Ethics Committee of the
      collage of Medical Veterinary and Life Sciences, Glasgow University approved the study.

      Preliminary session

      Before joining the study, preliminary session was conducted for ~3 hours. Participants were
      informed to come to the metabolic research unit at New Lister Building, Glasgow Royal
      Infirmary to completed physical activity readiness questionnaire (PARQ), healthy screening
      questionnaire and International physical activity questionnaire. Only participants at light
      or moderate of physical activity level, answered "no" to all questions in PARQ and were in
      generally good health were eligible to complete the preliminary session. Subsequently, height
      and body mass were measured and a ~30 min submaximal exercise test was conducted at gradually
      increasing inclines. After 4 minutes of warming up period (3.5 km/hr and 0% incline),
      participants were walking at a constant speed of 6 km/hr with incline being increased by 2%
      every 4 min. The test was terminated when the heart rate (HR) reached 85% of maximal HR
      (HRmax) defined as 220 - age in years. During the test, participants were wearing a HR
      monitor and a face mask (to measure rate of oxygen consumption (V̇O2) and rate of carbon
      dioxide production (V̇CO2)). The HR monitor and the mask were both connected to the indirect
      calorimetry machine (Quark RMR®, COSMED, Italy). The obtained data was used to predict
      maximal oxygen consumption (V̇O2max) which was achieved by extrapolation of the HR against
      V̇O2 in order to calculate workload corresponds to 60% of V̇O2max.

      Experimental trials

      A randomisation scheme was generated using GraphPad Software 2018© to allocate participants
      to the experimental trials. Trials were marked as Control and Exercise by the researcher.
      Each participant started first trial according to allocated trial randomization. On the
      morning of each experiment trial, participants reported to the metabolic research unit
      between 08:00 and 09:00 after an overnight fast. Height, body mass and resting metabolic rate
      (RMR) were measured. A cannula was introduced into an antecubital vein and after an interval
      of 10 min, a baseline blood sample was obtained. Subsequently, an appetite questionnaire was
      completed. Participants were then asked to either resting (Control trial) or exercising
      (Exercise trial) for one hour. The Exercise trials were conducted under controlled laboratory
      conditions. Participants were exercising on the treadmill (Trackmaster Treadmills, Full
      Vision, Inc., Kansas, USA) at speed and grade corresponding to 60% of their V̇O2max.
      Participants were wearing a HR monitor and a face mask while exercising, connected to
      indirect calorimetry equipment (Quark RMR®, COSMED, Italy). V̇O2 and V̇CO2 in the inspired
      and expired air were measured to calculate fat and CHO oxidation and rate of physical
      activity energy expenditure (PAEE) by using indirect calorimetry equations described by Frayn
      and Macdonald (1997).

      Subsequently, participants in both trials were presented to a standard isocaloric PKU type
      meal at 120 min. PKU meals in Exercise and Control trials were matched for weight content and
      macronutrient composition. Participants were asked to consume the entire meal within 20 min.
      Appetite questionnaires were obtained and blood samples were collected at 30, 60, 90 and 120
      pre-meal, 150, 180, 210, 240 and 300 min post-meal. Metabolic rate was measured every 30 min
      after each blood sample. After the completion of the last measurement, the participants were
      presented with an ad libitum buffet test meal which used to assess, under laboratory
      conditions, the spontaneous macronutrient and energy intake (EI). After completion of each
      trial, participants required to record their EI for the remainder of the experimental day
      using a self-recorded food diary. Water was available throughout the trials, but intake was
      replicated in the second trial and consumption time was matched. During the two days before
      the first trial, participants weighed and recorded all foods and drinks consumed and were
      asked to replicate this intake during the two days preceding the second trial.
    

Intervention name(s): PKU type meal and Exercise; PKU type meal
Intervention type(s): Other; Other
Intervention description(s): Exercise was conducted prior to PKU type meal.
PKU type meal was based on PKU special low protein foods (50% of total energy intake), natural free protein foods (37%) and protein substitute (13%). Calories provided in breakfast were 600 kcal and were not based on individual dietary requirement. 65% of total energy intake was provided from carbohydrate, 13% from protein and 22% from fat.; PKU type meal was based on PKU special low protein foods (50% of total energy intake), natural free protein foods (37%) and protein substitute (13%). Calories provided in breakfast were 600 kcal and were not based on individual dietary requirement. 65% of total energy intake was provided from carbohydrate, 13% from protein and 22% from fat.
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Basic Science