Effects of Energy and Physical Density Manipulation on Appetite
Condition: Appetite; Eating Behavior
Study type: Interventional

Summary: 
      As individuals tend to eat a constant weight or volume of food, manipulating physical and
      energy densities generally results in changes in energy intake without affecting subjective
      appetite sensations. However, relatively few studies have directly studied the interaction
      between physical and energy density manipulation. This study will determine the effects of
      foods that systematically vary in physical and energy density on ad libitum energy intake and
      subjective appetite ratings. Secondary outcomes will include gastrointestinal discomfort,
      fatigue and acceptability.
    

Detailed description: 
      A historical challenge for military personnel operating in austere, remote environments is
      the ability to pack and carry enough food to sustain their operational and nutritional needs.
      To address this challenge and meet Army modernization requirements, US Army ration developers
      are developing a new ration to provide a lightweight, low volume, energy dense daily combat
      assault ration. The ration will use novel food processing techniques that remove air and
      water to reduce volume and increase physical density (g/cc) and will provide a high relative
      fat content to increase energy density (kcal/g or kcal/cc). As individuals tend to eat a
      constant weight or volume of food, manipulating physical and energy densities generally
      results in changes in energy intake without affecting subjective appetite sensations.
      However, relatively few studies have studied the independent effects on appetite and energy
      intake of increasing physical and energy densities of foods to the extent being targeted by
      the new ration, and none has directly studied the interaction between physical and energy
      density manipulation. This study will address that gap by determining the effects of foods
      that systematically vary in physical and energy density on ad libitum energy intake and
      subjective appetite ratings. Secondary outcomes will include gastrointestinal discomfort,
      fatigue and acceptability. Using a randomized, crossover design consisting of four separate
      phases, 20 participants will be provided with a standard base diet and experimental foods in
      which physical and energy density are systematically varied using different levels of
      mechanical compression and aeration, and different proportions of fat and carbohydrate,
      respectively. Consumption of the experimental foods at each of the physical and energy
      density combinations will be compulsory for 1 day while intake of the standard diet will be
      ad libitum. Total energy and macronutrient intake will be measured by collecting uneaten food
      items. Additionally, perceived appetite, gastrointestinal symptoms, fatigue and acceptability
      of the experimental food products will be measured by questionnaire.
    

Intervention name(s): LPD+LED; HPD+LED; LPD+HED; HPD+HED
Intervention type(s): Other; Other; Other; Other
Intervention description(s): Low physical density (LPD) + low energy density (LED) foods. Participants receive breakfast, lunch and snack items engineered to have LPD and LED.; High physical density (HPD) + low energy density (LED) foods. Participants receive breakfast, lunch and snack items engineered to have HPD and LED.; Low physical density (LPD) + high energy density (HED) foods. Participants receive breakfast, lunch and snack items engineered to have LPD and HED.; High physical density (HPD) + high energy density (HED) foods. Participants receive breakfast, lunch and snack items engineered to have HPD and HED.
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Randomized, single-blind, crossover study
Masking: Single (Participant)
Primary purpose: Other
Keywords: Appetite; Eating behavior; Energy density