Impact of Energy Density on Energy Intake During Bed Rest
NCT Number: NCT06571877
Acronym: ED-REST
Status: ENROLLING_BY_INVITATION
Study Type: INTERVENTIONAL
Phases: NA
Conditions: Bed Rest|Space Analogue
Interventions: OTHER: Dietary intervention with manipulation of the energy density
Sponsor: University Hospital Tuebingen
Collaborators: DLR German Aerospace Center
Sex: ALL
Age: ADULT, OLDER_ADULT
Enrollment: 48
Study Design: Allocation: RANDOMIZED|Intervention Model: CROSSOVER|Masking: DOUBLE (PARTICIPANT, OUTCOMES_ASSESSOR)|Primary Purpose: BASIC_SCIENCE
Start Date: 2024-09-24
Completion Date: 2027-12-31
Locations: University Hospital Tuebingen, Tuebingen, Baden-Wuerttemberg, 72076, Germany

Summary:
Brief summary: This study is conducted in the context of a 60 days strict bed-rest study with 6° head-down-tilt (HDT) body position. Food intake can be challenging during bed-rest due to loss of appetite and constantly feeling full. The study aims to assess whether or not energy intake varies during a meal when the energy density of a meal is increased by the fat content. This experiment follows a crossover design with repeated measures within subjects. The order of experimental conditions is balanced among participants and sex, and the assignment of orders to participants is randomly. On each test day, participants are provided with breakfast, lunch, and dinner as usual. Across test days, the ED of breakfast (24 participants) or lunch (24 participants) is modified to two levels: the standard level and an increased level (+ 0.42 kcal/g compared to the standard). The meals are adjusted in energy density without noticeable changes in appearance or taste. These meals have identical ingredients, but the macronutrient proportions are modified. Entrées with increased fat content are prepared by incorporating neutral-tasting vegetable oil into the standard recipes. Participants receive their meals and are given the flexibility to eat ad libitum for 45 minutes. To comply with the strict bed rest rules, the next meal will be used for counterbalancing total energy intake over the day if necessary. In case of problems, a nutrient drink could be used to assure the requested total energy intake in order to maintain body weight.The experiments are conducted during 4 campaigns, each campaign consisting of 12 participants.

Primary Outcome Measures: Energy intake in kcal, Energy intake is calculated by measuring the amount of food before and after the experiment and precalculation of the energy content of the meals, Measurments taken at days 6, 8, 51 and 53 in the 60 days head down tilt period.
Secondary Outcome Measures: Amount of food intake in g, The amount of food intake is calculated by measuring the amount of food before and after the experiment, Measurments taken at days 6, 8, 51 and 53 in the 60 days head down tilt period.|Composite appetite score measured by 10 cm visual analogue scales (VAS), Appetite perception is measured using validated 100 mm VAS for hunger, satisfaction, fullness, and prospective food consumption (Flint et al., 2000). The composite score is calculated as follows: (\[hunger + prospective food consumption + (100-fullness) + (100-satisfaction)\]/4) by Stubbs et al., 2000, Measurments taken at days 6, 8, 51 and 53 in the 60 days head down tilt period before the meal, 30 minutes, 45 minutes and 60 minutes after the meal and directly before the next meal (either lunch or dinner)|Visual analogue scale for perception of portion size, Portion size is measured using a 100 mm VAS., Measurments taken at days 6, 8, 51 and 53 in the 60 days head down tilt period before the meal, 30 minutes, 45 minutes and 60 minutes after the meal and directly before the next meal (either lunch or dinner)|Emotional response, Emotional response is used using the Self assessment manikin (Bradley \& Lang, 1994), Measurments taken at days 6, 8, 51 and 53 in the 60 days head down tilt period before the meal, 30 minutes and 60 minutes after the meal and directly before the next meal (either lunch or dinner)|Number of participants assigned to countermeasures for consequences of long-term bed rest, During bed rest, the participants are allocated to 4 arms of different countermeasures for consequences of long-term bed red which is independent of this food study. These countermeasures include: Arm 1: Electrical Muscle Stimulation; Arm 2: Proprioceptive Training; Arm 3: Exercise plus proprioceptive Training; Arm 4: Control.

This information on "bed rest countermeasure" will be added as a co-variate., Allocation to countermeasure test arms is done ahead of the bed rest study, at least 4 weeks ahead bed rest.