Behavior
Conditions
Keywords
ketones, human cognition, metabolism, anxiety, intervention
Brief summary
The study will examine the effect of exogenous ketone ester on behavior and metabolism using Virtual Reality and computerizes behavioral tasks.
Detailed description
This study investigates the effects of exogenous ketone ester on behavior, cognition, and metabolism over one week of consumption. Using a within-subjects, randomized, crossover design, participants will undergo two phases: one with the ketone ester supplement and one with a calorie- and taste-matched placebo. The study includes four lab visits: visits 1 and 3 mark the first day of each intervention, while visits 2 and 4 mark the last day. During each visit, participants will complete behavioral tasks, questionnaires, and blood tests. Additionally, participants will record their food intake via an app and collect stool samples throughout the intervention.
Interventions
DIETARY_SUPPLEMENTketone ester
oral supplement
DIETARY_SUPPLEMENTdextrose (placebo)
oral supplement calorie and taste matched to ketone supplement
Sponsors
German Institute of Human Nutrition
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* Consent to participate * Fluent in German * Physically healthy. No regular medication * No drug use 1 week prior to the study * BMI 18-31 kg/m2
Exclusion criteria
* Former or current illnesses of: * Brain or mind (including eating disorders, personality disorders, alcohol, drugs or drug dependence, neurological disorders other than occasional headache; depression or anxiety disorder excluded) * Heart or blood circulation * Gastro-intestinal or endocrine disorders * Liver or kidney disorders * Electrolyte imbalance * Other serious past or present medical conditions (for example, metabolic syndrome, diabetes, cancer) * Pregnancy * Extreme athletes (\>2h/day intense work-out; casual cycling or walking is ok) * Menopause (post menopause is ok) * Ketogenic diet, ketogenic supplement intake, intermittent fasting or calorie restricted diet during preceding 4 weeks of study participation * Fear of blood draw
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Anxiety behavior in Virtual Reality | on day 8 of each intervention arm (visit 2 and 4) | Using different scenes in Virtual Reality, parameters of motion behavior such as speed (measured in meters per second) and distance walked (measured in meters) will be assessed using motion tracking technology. These measurements will be combined to generate a composite score of anxiety-related motion behavior. |
| Risk propensity on a decision-making task | on day 8 of each intervention arm (visit 2 and 4) | The choice (accept/reject) between a risk/gamble or safe option, based on a task paradigm by Liu et al. (2021) |
| Competitive confidence in a competition task | on day 8 of each intervention arm (visit 2 and 4) | based on a task paradigm by Goette et al., 2015 |
| Delay Discounting behavior in a computerized task | on day 1 of each intervention arm (visit 1 and 3) | based on a task paradigm by Eisenstein et al. 2015 |
| Performance in Dual Task | on day 1 of each intervention arm (visit 1 and 3) | based on a task paradigm by Szameitat et al., 2002 |
| Levels of ketones (ß-Hydroxybutyrate) | baseline, 15, 30, 60, and 90 minutes post drink-consumption on each of the 4 visits | Blood samples |
| Insulin | baseline, 15, 30, 60, and 90 minutes post drink-consumption on each of the 4 visits | Blood samples |
| Ghrelin | baseline and + 90 minutes post drink-consumption on each of the 4 visits | Blood samples |
| Glucose Values | every 15 Minutes from visit 1 to visit 2 and again from visit 3 to visit 4 | Continuous Glucose Monitoring through sensors applied to skin |
| Blood Glucose | baseline, 15, 30, 60, and 90 minutes post drink-consumption on each of the 4 visits | Blood samples |
| Levels of cortisol | baseline, 15, 30, 60, and 90 minutes post drink-consumption on each of the 4 visits | Blood samples |
| Electrocardiogram (heart rate) | between 30 and 60 minutes post drink-consumption on each of the 4 visits | Electrophysiological recording |
| Electrocardiogram (heart rate variability) | between 30 and 60 minutes post drink-consumption on each of the 4 visits | Electrophysiological recordings |
| Electrodermal Activity | between 30 and 60 minutes post drink-consumption on each of the 4 visits | Electrophysiological recordings |
| Subjective anxiety levels | on day 8 of each intervention arm (visit 2 and 4) | reported by participants on visual analog scale (1-7) during Virtual Reality. 1 being no anxiety to 7 being high anxiety |
| Subjective stress levels | on day 8 of each intervention arm (visit 2 and 4) | reported by participants on visual analog scale (1-7) during Virtual Reality. 1 being no stress to 7 being high stress |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Chronotype Questionnaire | baseline (visit 1) | Morningness-Eveningness Questionnaire (MEQ; Horne & Östberg, 1976) |
| Stress Questionnaire | baseline, and on day 8 of each intervention arm (visit 1, 2, and 4) | Perceived Stress Questionnaire (PSQ; Fliege et al. 2001) |
| Gut microbiome | on day 8 of each intervention arm (visit 2 and 4) | Assessed via stool samples after each intervention |
| Subjective stress levels | 5 days of each intervention arm | reported via FoodApp once per day |
| Subjective anxiety levels | 5 days of each intervention arm | reported via FoodApp once per day |
| Daily food intake | 5 days of each intervention arm | Self-reported food intake recorded via FoodApp or handwritten food diary |
| Trait Anxiety Questionnaire | baseline before visit 1 | Trait version of State-Trait Anxiety Inventory (STAI; Grimm et al. 2009). High scores mean high trait anxiety. |
| State Anxiety Questionnaire | on day 1 and 8 of each intervention arm (visit 1,2,3,4) | State version of State-Trait Anxiety Inventory (STAI; Grimm et al. 2009). High scores mean high state anxiety. |
| Interoception Questionnaire | on day 8 of each intervention arm (visit 2 and 4) | Multidimensional Assessment of Interoceptive Awareness (MAIA; Bornemann et al. 2015). High scores mean high interoceptive ability. |
| Depression Questionnaire | baseline, and on day 8 of each intervention arm (visit 1, 2, and 4) | Becks Depression Inventar (BDI; Kühner et al. 2007). High scores mean high depression scores |
| Mood Questionnaire | on day 1 and 8 of each intervention arm (visit 1,2,3,4) | Positive and Negative Affect Schedule (PANAS; Janke et al. 2014). High score on positive scale mean high positive mood and high scores on negative scale mean high negative mood. |
| Inhibition Questionnaire | baseline (visit 1) | Behavioral Inhibition and Activation (BISBAS; Strobel et al. 2001). High scores on inhibition scale mean high inhibition and high scores on activation scale mean high activation. |
| Impulsivity Questionnaire | baseline (visit 1) | Barratt Impulsiveness Scale (BIS; Barratt et al. 1965). High scores mean high impulsivity. |
| Social Anxiety Questionnaire | baseline, and on day 8 of each intervention arm (visit 1, 2, and 4) | Liebowitz Social Anxiety Scale (Heimberg et al. 1999). High scores mean high scoial anxiety |
| Flow Questionnaire | on day 1 of each intervention arm (visit 1 and 3) | Flow state scale (FSS; Rheinberg et al. 2002) asked after Dual Task. High scores mean more flow experience during the dual task. |
| Emotional Eating Questionnaire | baseline (visit 1) | Salzburg Emotional Eating Scale (SEES; Meule et al. 2018) |
| Stress Eating Questionnaire | baseline (visit 1) | Salzburg Stress Eating Scale (SSES; Meule et al. 2018) |
| Dominance Questionnaire | baseline, and on day 8 of each intervention arm (visit 1, 2, and 4) | Social Dominance and Aggressive Dominance Scale (Kalma et al. 1993) |
| Autonomy Questionnaire | on day 8 of each intervention arm (visit 2 and 4) | Basic Psychological Need Satisfaction and Frustration Scale (BPNSNF; Heissel et al. 2019) |
| Personality Questionnaire | baseline (visit 1) | Big Five Inventory (BFI; John et al. 1991) |
Countries
Germany
Contacts
Primary ContactBeatrix Keweloh
Backup ContactSoyoung Q Park, Prof.
Outcome results
None listed