The Covid-19 pandemic that made it impossible to conduct within the timeframe.

Based on in vitro studies identifying changes in food structures potential to delay digestion as well as results from animal studies showing potential of these foods to decrease appetite, nano-particulated whey protein and high molecular weight whey protein-alginate coacervates were chosen to be investigated in humans. Thereby, the aim of this short-term study is to investigate if nano-particulated whey protein has appetite reducing effects in humans compared to non-particulated whey protein (Part 1) as well as if high molecular weight whey protein-alginate coacervates have appetite reducing effects in humans compared to calcium alginate (Part 2).

Based on animal studies in mice, nano-particulated whey protein and high molecular weight whey protein-alginate coacervates are expected to have appetite reducing (and potentially also other) effects, which potentially may be beneficial for body weight management. In order to investigate these effects in humans, this study is divided into two parts (Part 1 and Part 2), of which the specific objectives are specified below:

Part 1: The objective of this part of the study is to examine if nano-particulated whey protein can reduce appetite compared with non-particulated whey protein.

Part 2: The objective of this part of the study is to examine if high molecular weight whey protein-alginate coacervates can reduce appetite compared to calcium alginate.

A double-blind, randomised crossover design with four arms divided into the two parts will be applied. After having successfully completed screening procedures, eligible participants will be invited to two separate appetite probe days with particulated whey protein followed by at least 14 days break followed by another two separate appetite probe days with the whey protein-alginate coacervates. The appetite probe days must be separated by at least 7 days, but there is no upper limit for days in between, as long as the participants remain weight stable and do not change diet or physical activity level significantly. The study includes a total of five visits to the study site.

For standardisation, 48 hours before the appetite probe days, the participants will be asked to consume a regular diet compliant to what they usually eat and no excessive alcohol consumption (not above 5 units and no alcohol at all from 8 pm the night before the appetite probe days) or intense physical activity is allowed. Within each part of the study, the participants will be instructed to consume similar meals the evening before the appetite probe days and the meal must be consumed at approximately the same time. The participants will also be instructed to go to bed at the same time in the evening prior to the appetite probe days. Additionally, the participants must arrive at the study facilities in the morning after an overnight fast (from 10 pm) using non strenuous means of transportation. Furthermore, over the course of the study (from screening (visit 1) to completion of the last appetite probe day (visit 5)), the participants are not allowed to change body weight (±3 kg), diet or physical activity level (as judged by the sub-investigator). The participants will be weighed and asked about compliance with additional standardisation criteria in a room away from the other participants before initiating each appetite probe day. Possible non-compliance with the standardisation will be judged whether to result in re-scheduling of the visit or to be recorded as a protocol deviation.

Participants arrive at the study facility in the morning. Compliance with standardisation is controlled along with registration of possible adverse events and use of concomitant medications. During the appetite probe days, participants are settled together in an open office, where they are separated at individual tables. During the ad libitum lunch, participants are settled into individual feeding cubicles, where they cannot see each other and are instructed not to talk to each other.

VAS' will be completed for measurement of fasting levels of self-reported appetite.

The test products will be provided as a standardised fixed breakfast and as a standardised fixed mid-morning meal provided 3 hour and 1 hour prior to the ad libitum lunch, respectively.

Immediately before and after the test products and the ad libitum lunch and at 30 minutes intervals, VAS' will be completed assessing self-reported appetite.

After the ad libitum lunch, the participants will be free to leave the laboratory. They will be provided with a snack box including a variety of foods to including a ready-to-heat dish for dinner etc. providing approximately 10000 kJ. The participants will be instructed only to consume foods and drinks (water excepted) from the snack box for the remaining of the days, and to be focussed while eating and only eat until feeling comfortably full. The participants will be instructed to complete a diary registering the time point of consumption of which items from the snack box (and potential additional items). If consuming any foods or energy containing drinks besides those provided in the snack box, the participants will be instructed to register the type and amount consumed. Within the diary, the participants will also be instructed to register the time of going to bed on the day of the appetite probe day. At the second appetite probe day within each part of the study, the participants will be instructed to go to bed at approximately the same time as registered at the first appetite probe day within each part of the study. On the following day after each appetite probe day, the participants will be instructed to hand in the leftovers from the snack box and the diary at the research facility.

Inclusion Criteria:

• Participants who have provided written informed consent
• Healthy men and women (at least 40% of each gender)
• Age between 18 and 45 years
• BMI between 22.0-30.0 kg/m2
• Regular breakfast eaters (eating breakfast ≥ 4 times a week)

Exclusion Criteria:

• Participants unable to consume the test products (the test product will be presented at screening)
• Participants not able to comply with the study protocol, including consumption of the specific study foods served during lunch and in the snack box (the study foods will be presented at screening)
• Any known food allergies or food intolerance likely to affect the present study
• Significant health problems as judged by the principal investigator
• Taking any medication or supplements known to affect appetite or body weight within the past month and/or during the study, as judged by the principal investigator
• Smoking, smoking cessation within the past 3 months or nicotine use (electronic cigarettes, gum etc.). Irregular smokers accepted
• Self-reporting currently dieting or having lost/gained significant amount of weight (±3 kg) in the previous 3 months
• Significant weight changes (±3 kg) over the course of the study (from screening to completion of last appetite probe day)
• Significant changes in physical activity patterns in the past 4 weeks or significant changes over the course of the study (from screening to completion of last appetite probe day), as judged by the sub-investigator
• Significant changes in diet in the past 4 weeks or significant changes over the course of the study (from screening to completion of last appetite probe day) as judged by the sub-investigator
• Participants who work in appetite related areas
• Simultaneous or within the past month participating in other clinical trials that can interfere with the study

Self-reporting

No IPD will be shared

Double-blind