Healthy
Conditions
Keywords
ketone bodies, appetite control, macronutrient oxidation, metabolic chamber, exogenous ketones
Brief summary
Aim of the study is to compare the origin of ketone bodies: endogenous ketone bodies due to 36 hours fasting or 24 hours of ketogenic diet vs. exogenous ketone bodies as supplements additional to normal diet. Secondary aim of the study is to validate the new metabolic chambers.
Detailed description
Each study week starts with a 3-day run-in period with controlled diet at home and ends with a test-meal (breakfast) in the lab and following food record over the rest of the day at home. 1. week: physical activity level (PAL) 1.3, 3 intervention days in the metabolic chamber: ad libitum energy intake, washout day, isocaloric diet, 36 hours fasting 2. week: physical activity level (PAL) 1.3, 2 intervention days in the metabolic chamber: isocaloric diet, 36 hours fasting 3. week: physical activity level (PAL) 1.6, 2 intervention days in the metabolic chamber: ad libitum energy intake, 36 hours fasting 4. week: physical activity level (PAL) 1.6, 2 intervention days in the metabolic chamber: isocaloric diet, ketogenic diet (isocaloric) 5. week: physical activity level (PAL) 1.6, 2 intervention days in the metabolic chamber: isocaloric diet, isocaloric diet + ketone body supplements (isocaloric)
Interventions
DIETARY_SUPPLEMENTBeta-Hydroxybutyrate as Ca-Mg-salt, active
24 hour intervention with ketone body supplements additional to a normal diet (isocaloric diet in total) to induce ketosis (exogenous ketone bodies), in a metabolic chamber at physical activity level of 1.6, after one day of isocaloric diet in a metabolic chamber at physical activity level of 1.6.
DIETARY_SUPPLEMENTketogenic diet (KetoCal® 4:1 Neutral, Nutricia GmbH, Erlangen, Germany), active
24 hour interventions with ketogenic isocaloric diet to induce ketosis (endogenous ketone bodies), in a metabolic chamber at physical activity level of 1.6, after one day of isocaloric diet in a metabolic chamber at physical activity level of 1.6.
DIETARY_SUPPLEMENTfasting, active
36 hours of fasting, in a metabolic chamber at physical activity level of 1.6, after one day of isocaloric diet in a metabolic chamber at physical activity level of 1.6.
DIETARY_SUPPLEMENTfasting, inactive
36 hours of fasting, in a metabolic chamber at physical activity level of 1.3, after one day of isocaloric diet in a metabolic chamber at physical activity level of 1.3. The same intervention is reproduced one week later.
Sponsors
University of Kiel
Study design
Allocation
NON_RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
all subjects are undergoing each intervention
Eligibility
Sex/Gender
ALL
Age
20 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* healthy * BMI 19-29 kg/m2 * low-medium habitual physical activity * women using hormonal contraceptive
Exclusion criteria
* smoking * chronic illnesses * food allergies / intolerances * vegans and vegetarians * regular high physical activity (exercise \>1 hour/d) * current weight loss diet / weight loss of \>5 kg in the last 3 months * pregnant / lactating women * persons incapable of giving informed legal consent
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| appetite control - satiety quotient | 30 min | satiety quotient of standard test-breakfast after 24 hours of intervention |
| appetite control - ghrelin | 24 hours | ghrelin concentration in plasma (24 hour AUC) |
| appetite control - GLP-1 concentration in plasma | 24 hours | Glucose Like Peptide-1 concentration in plasma (24 hour AUC) |
| appetite control - PYY concentration in plasma | 24 hours | Peptide YY concentration in plasma (24 hour AUC) |
| appetite control - subjective feelings of hunger | 24 hours | measured with visual analogue scales (24 hour AUC). The scale consists of a 10 cm vertical line anchored with not hungry at all at the left side and with extremely hungry at the right side. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| macronutrient oxidation | 24 hours | measured with indirect calorimetry in a metabolic chamber |
| energy expenditure | 24 hours | measured with indirect calorimetry in a metabolic chamber |
| glycemia - glucose AUC | 24 hours | glucose AUC from continuous glucose monitoring data |
| repeatability of energy expenditure measurements | 24 hours | repeated measurement of 24h-energy expenditure in a metabolic chamber on inactive isocaloric and fasting days |
| ß-Hydroxybutyrate concentration in serum | 24 hours | 24 hour ß-Hydroxybutyrate concentration in serum (AUC) |
Countries
Germany
Outcome results
None listed