Acute Effects of Ultra-processed Versus Unprocessed Foods on Glucocorticoid Secretion in Healthy Individuals

Not Applicable

Recruiting

Brief Summary: The investigators aim to understand whether the acute cortisol response to food differs between differently processed foods.

In this monocentric, randomized, cross-over, open-label study, 20 healthy volunteers will receive two differently processed meals of similar caloric content and composition. The study will primarily focus on changes in blood cortisol levels, but other metabolic parameters will also be compared.

Detailed Description: Obesity is one of the most serious health problems of the 21st century, with ultra-processed diets being a major driver of the current obesity pandemic. Understanding how these diets affect body weight is critical to identifying new treatment targets. Current evidence suggests that the degree of food processing may affect cortisol secretion, a hormone that plays a key role in body weight regulation by increasing with acute food intake and promoting energy storage in adipose tissue. However, whether ultra-processed foods enhance cortisol response has not been thoroughly investigated.

Here, the investigators aim to understand the reaction of GCs in response to different processed foods in healthy volunteers. No medication will be used in this study.

Participants will be asked to refrain from strenuous physical activity and alcohol consumption for 24 hours prior to the study. They will fast for 12 hours before consuming a high-calorie, low-processed meal. After fasting again, participants will consume a high-calorie, ultra-processed meal on a second study day. The order of the meals is not fixed. The study will include a screening visit and two study visits.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Severe acute or chronic disease
Lactose intolerance
Severe food allergy
Casual smoking (more than six cigarettes per day)
Frequent, heavy alcohol consumption (more than 30g/day)
Frequent, heavy caffeine consumption (more than 4 caffeinated drinks/day)
Regular physical exercise (more than 4hrs per week)
Shift work
Previous enrollment in a clinical trial within the past two months
Intake of any steroid-containing drugs, including topical steroids and inhalers, within four weeks of the study initiation
Contradictions to undergo the investigated intervention
Inability or unwillingness to provide informed consent

Primary Outcome Measures

Name	Time	Method
Blood cortisol change	Up to six weeks	Change in blood cortisol assessed by repeadidly collecting blood before and after the meal

Secondary Outcome Measures

Name	Time	Method
Energy expenditure (basal metabolic rate, diet-induced thermogenesis	Up to six weeks	Basal metabolic rate measured with indirect calorimetry
Substrate utilization (respiratory quotient)	Up to six weeks	Respiratory quotient assessed with indirect calorimetry
Body composition	Up to six weeks	Body impedance analysis before meal
Satiety	Up to six weeks	Appetite rating with visual analogue scale (VAS) from 0mm-100mm (0mm=not at all and 100mm=extreme)
Weight	Up to six weeks	Measurement of weight with a standard scale
Motivation to eat	Up to six weeks	Motivation to eat measured with a speed clicking test
Systolic and diastolic blood pressure	Up to six weeks	Assessment of blood pressure with a standard blood pressure monitor
Lipids (total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides)	Up to six weeks	Blood collection fasted
Perceived stress	Up to six weeks	Measured by perceived stress questionnaire
C-peptide	Up to six weeks	Change in blood cortisol assessed by repeadidly collecting blood before and after the meal
Insulin	Up to six weeks	Change in blood cortisol assessed by repeadidly collecting blood before and after the meal
Blood glucose	Up to six weeks	Change in blood glucose assessed by repeadidly collecting blood before and after the meal
Neuroendocrine hormones (thyroid hormones, GLP1, glucagon, ACTH)	Up to six weeks	Change in blood cortisol assessed by repeadidly collecting blood before and/or after the meal