Inclusion Criteria:
* right-handed
* legally competent
* physically and mentally healthy
* BMI: 19-35 kg/m²
* fluent in reading and speaking German
Exclusion Criteria:
* weight change \>5% of body weight during the last 3 months
* pregnancy or breastfeeding
* allergies (inclusion possible after consultation with study doctor)
* history of cardiovascular disease (myocardial infarction, stroke, hypertension, hypotension) in the last year
* severe psychiatric condition, including drug addiction and depression
* impaired renal or liver function
* dementia or other severely debilitating cognitive disease
* history of or current eating disorders (e.g., Bulimia nervosa, Anorexia nervosa, Orthorexia nervosa, Binge-Eating disorder)
* chronic diseases (e.g., Morbus Crohn, Colitis Ulcerosa)
* metabolic disorders (e.g., metabolic syndrome, diabetes type 1 or 2)
* hormonal imbalances (e.g., thyroid gland diseases)
* consuming diseases (e.g., cancer, kachexie) in the last 2 years
* surgical removal (partial removal) of the digestive organs (e.g., gastrectomy) or history of bariatric surgery
* Autoimmune conditions or current infection
* Blood clotting disorders (e.g., haemophilia)
* Severe anemia
* severe claustrophobia
* blood donation four weeks prior to study entry
* glucocorticoid therapy (oral)
* anticoagulant medication (inclusion possible if medication can be paused)
* taking medications that require regular eating
* any medications or supplements known to affect sleep, circadian rhythms, immune activity or metabolism
* taking weight loss, lipid or glucose-lowering medications (any medications that affects metabolism) i.e. metformin
* pacemaker or other electrical implant
* vaccination during the study course or in the two weeks' prior
* immunosuppressive premedication
* currently on a diet/fasting regime (or within 1 month)
* professional athletes
* nicotine consumption
* drug abuse
* alcohol consumption per week more than 14 beers (0,3l)/ wine (0,125l)/ sparkling wine (0,1l)/Schnaps (4cl)
* shift work
* poor sleep quality (PSQI score \> 10 at medical screening)
* travel across more than one time zone one month before study or during study period
* non-removable metallic implants
* fear of blood draw
