Effects of a Single Day of Mixed Macronutrient Overfeeding on Energy Balance and Metabolic Responses
Condition: Metabolic Disease; Appetitive Behavior
MeSH terms: Metabolic Diseases
Study type: Interventional

Summary: 
      Healthy male participants are recruited to observe potentially deleterious changes in
      appetite regulation and metabolic control. Participants will be provided with an energy
      intake representative of their daily requirements on the first day of one trial and will be
      provided with an additional 50% energy intake on the first day of another trial. Outcome
      variables will be assessed during the second day of each trial in response to a fixed mixed
      macronutrient meal tolerance test.
    

Detailed description: 
      All testing will take place within the Carnegie Research Institute, Leeds Beckett University.
      We will ask all the participants to visit on five occasions for the completion of a
      preliminary screening trial and two single-blind counterbalanced experimental trials which
      each require the participants to visit the laboratory on two consecutive days. The
      experimental trials will be separated by a minimum of one week.

      Visit 1: Preliminary Screening:

      Before an individual can take part in the experiment, they will need to undergo screening.
      Individuals will need to complete a Health Screen Questionnaire. Individuals will be excluded
      from the study if they are not currently in good health, have any condition that would alter
      their metabolism and/or have had significant medical problems in the past that may affect the
      outcomes of the study. Individuals will also be asked to be complete a Three-Factor Eating
      Questionnaire, to check that they are not restrained eaters, and an International Physical
      Activity Questionnaire (IPAQ) to ensure that all participants are either sedentary or
      moderately active. All individuals will be asked to confirm that they have been weight stable
      for at least six months before participating and that they are not currently dieting. Height,
      body mass and age will be collected to calculate the energy requirements for the main trials
      based on the Mifflin equation.

      Visits 2, 3, 4 and 5: Experimental Trials:

      The participants will be asked to record their food intakes and activity patterns during the
      three days prior to the first experimental test using a food and physical activity diary.
      They will then be instructed to repeat this diet and activity pattern prior to the second
      experimental trial. Participants will be required to arrive at the laboratory for all
      experimental trials after an overnight fast of at least 10 hours and having refrained from
      any strenuous activity for 48 hours, and alcohol and caffeine consumption in the previous 24
      hours. Two hours before arriving at the laboratory on the day of the experimental trials,
      participants will be required to ingest 300 mL of water to standardise hydration levels for
      the trial.

      During Day One of each experimental trial, participants will consume a porridge-based
      breakfast, soup- and pasta-based lunch, and rice-based evening meal under laboratory
      observation. The meals will contain macronutrient contents representative of current dietary
      recommendations of 50% carbohydrate, 15% protein and 35% fat. These meals have been selected
      to facilitate manipulation of the energy content, while matching the meals for appearance and
      palatability. During one trial, these meals will provide the calculated energy requirement
      for each individual based on the Mifflin equation and a physical activity factor of 1.4. The
      meals will be covertly manipulated to provide an additional 50% energy intake during the
      other trial. The provision of 150% of the estimated energy requirements for participants has
      been used in previous research for five day periods but will only be provided for a single
      day in the present study. Participants will be required to consume all of the diet during the
      standardised phase (i.e. either their daily energy requirements or the 50% overfeed) and will
      be blinded to the energy content of the trials. After the consumption of the evening meal
      (~6pm), participants will have fulfilled the requirements for day one and will be asked not
      to consume any food prior to returning to the laboratory between 7am and 9am the next
      morning.

      On Day Two of each experimental trial day, participants will arrive at the laboratory after
      an overnight fast and an Introcan Safety Cannula will be placed into a vein in the
      anticubital space for regular venous blood sampling. Blood samples will be collected in the
      fasted state and every 30 min after consumption of a standardised breakfast for a period of
      three hours. After the collection of the final blood sample, the cannula will be removed and
      participants will be provided with an ad libitum pasta meal (50% carbohydrate, 15% protein,
      35% fat) for the assessment of energy intake. Participants will consume ad libitum meals in
      isolation to prevent any social influences and will be instructed to eat until 'satisfied'.
    

Intervention name(s): Overfeed; Energy Balance
Intervention type(s): Other; Other
Intervention description(s): Participants consume energy intakes that are 50% higher than their estimated requirements instead of consuming energy intakes equal to their estimated requirements; Participants consume energy intakes equal to their estimated requirements instead of consuming intakes that are 50% higher than their estimated requirements
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Single blind, counterbalanced, crossover trial
Masking: Single (Participant)
Primary purpose: Prevention