Physiological and Sensory Responses to Prolonged Fasting in Humans

Inclusion Criteria: * • Body mass index 20.0-29.9 kg∙m-2 * Age 18-45 years * Willing to abstain from food intake for just over 3 days (\~82 hours) * Able and willing to provide informed consent and safely comply with study procedures * Females to maintain record of regular menstrual cycle phase or contraceptive use * No anticipated changes in lifestyle during the study (e.g. holidays or exercise programmes) Exclusion Criteria: * • Any reported condition or behaviour deemed either to pose undue personal risk to the participant or introduce bias * Any diagnosed metabolic disease (e.g. type 1 or type 2 diabetes) * Any reported use of substances which may pose undue personal risk to the participants or introduce bias into the experiment * Pregnancy * Breastfeeding * Lifestyle not conforming to standard sleep-wake cycle (e.g. shift worker) * History of eating disorders (e.g. anorexia) * Any reported recent (\<6 months) change in body mass (± 3%) * Uncontrolled hyperthyroidism * Advanced cerebrovascular insufficiency or dementia * Advanced liver or kidney insufficiency * History of migraine and or headache * Psychotic disorders * Unstable or severe coronary artery disease * Retinal detachment * Duodenal or stomach ulcer * Cancer and malignant disease * Regular use of Non-steroidal anti-inflammatory drugs (NSAIDs) * Use of Systemic corticoids * Use of Antihypertensives (especially beta-blockers and diuretics) * Use of Antidiabet…