Effect of Tableware Visual Cues on Portion Control and Eating Rate
Condition: Portion Size
Study type: Interventional

Summary: 
      Randomised within subjects cross-over study (n=94) exploring the cognitive and physiological
      processes associated with portion control. Participants will eat a self-served lunch using a
      portion control plate vs. a conventional (control) plate on two separate occasions under a
      controlled laboratory environment. Portion size, meal micro-structure, attention, memory and
      satiety markers will be analysed. The portion control plate is a prototype designed in
      collaboration with the commercial partner for this study and is based on published evidence.
      It includes sectors and pictures indicating amounts to serve from starchy food, protein and
      vegetables. The control plate will be of the same background colour, size and shape but
      without any pictures or demarcations. The main study outcome is attention time on areas of
      interest in the plate corresponding to main foods groups, across plate conditions.
    

Detailed description: 
      The size and design of tableware have been proposed as a potentially effective strategy to
      modulate how much is eaten at a meal. The mechanisms by which specific tableware may work
      however are not known, in particular the cognitive processes associated with visual stimuli.
      In this covert trial, 68 women (34 overweight or obese) and 26 lean men (exploratory
      sub-study) will self-serve and consume food from a laboratory buffet using a portion control
      plate with visual stimuli for appropriate amounts of main food groups, or a conventional
      plate, on two different days in random order. On both sessions participants will complete
      behavioural and cognitive tests to measure visual attention during the meal (eyetracking
      device), meal microstructure (Universal Eating Monitor), episodic memory for portion sizes
      (computerised test), portion size choice, food intake, subjective appetite and satiety,
      cephalic and intestinal satiety responses. Further behavioural tests include meal liking,
      expected satiety, portion size perceptions and tool acceptance ratings. The main study
      outcome is difference in proportional dwell time on areas of interest in the plate
      corresponding to main foods groups (women), or difference in bite size (men) across
      conditions. Secondary outcomes for all subjects include: portion size for overall meal and
      meal components, eating rate, bite size, deceleration rate, portion size memory error,
      portion size norms, portion control self-efficacy, tool acceptance, energy compensation for
      the rest of the day, plus blood insulin, glucose, pancreatic polypeptide and ghrelin up to 90
      min post-meal (sub-sample of 34 women, 50% being overweight/obese). Analyses by gender and
      BMI sub-groups will be applied when possible. The results of this study will help to better
      understand the potential mechanisms by which portion control tools with visual cues may work,
      and to improve the design of current instruments for their application in nutritional
      interventions.
    

Intervention name(s): Portion control plate; Conventional plate
Intervention type(s): Device; Device
Intervention description(s): Portion control plate including demarcations and pictures for recommended amounts of main food groups (starch, protein and vegetables), 25 cm in diameter, enamel, white background.; Conventional plate without demarcations or images, 25 cm in diameter, enamel, white.
Other intervention name(s): Calibrated plate; Control plate
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Randomised, cross-over (within-subjects) design.
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Portion control plate; Visual attention; Eating rate; Cephalic satiety response