Inclusion Criteria:

1. Healthy as assessed by the health and lifestyle questionnaire, physical examination and results of the pre-study laboratory tests;
2. Males aged between 18 - 60 years at Day 01 of the study;
3. Normal weight subjects and overweight/obese subjects, Body Mass Index (BMI) will be at least two units different between the heaviest normal weight and the lightest overweight subject, the largest contrast between groups will be aimed at, e.g normal weight BMI between 18 and 25 kg/m2 and overweight/obese BMI between 27.5-35 kg/m2;
4. Regular Dutch eating habits as assessed by P6468 F02 and used to breakfast consumption;
5. Non restrained eater, defined as a score of < 2.5 in lean and <3.25 in obese men on the Dutch Eating Behaviour Questionnaire;
6. Appropriate veins for blood sampling/cannula insertion according to TNO;
7. Voluntary participation;
8. Having given written informed consent;
9. Willing to comply with the study procedures;
10. Willing to accept use of all nameless data, including publication, and the confidential use and storage of all data for at least 15 years;
11. Willing to accept the disclosure of the financial benefit of participation in the study to the authorities concerned.

Exclusion Criteria:

1. Participation in any clinical trial including blood sampling and/or administration of substances up to 90 days before Day 01 of this study;
2. Participation in any non-invasive clinical trial up to 30 days before Day 01 of this study, including no blood sampling and/or oral, intravenous, inhalatory administration of substances;
3. Having a history of medical or surgical events that may significantly affect the study outcome, including any psychiatric history, and metabolic or endocrine disease, or any gastro-intestinal disorder or hypertension;
4. Use of medication that may influence appetite, and/or sensory functioning within 14 days before day 01, except paracetamol;
5. Allergic reaction to chlorhexidine and/or lidocaine (anaesthetic solution);
6. Having a history of or current alcohol consumption of more than 28 units/week;
7. Reported unexplained weight loss or gain of > 2 kg in the month prior to the pre-study screening;
8. Mental or physical status that is incompatible with the proper conduct of the study;
9. Reported chronic and/or excessive mental or physical strain;
10. Reported slimming or medically prescribed diet;
11. Reported vegan, vegetarian or macrobiotic;
12. Use food supplement(s) and not willing to stop intake after the medical screening;
13. Smoking;
14. Claustrophobia;
15. Practicing heavy physical exercise > 5 hours/week;
16. Recent blood donation (<1 month prior to the start of the study) and not willing to give up blood donation during the study;
17. Personnel of TNO Quality of Life, their partner and their first and second degree relatives;
18. Not having a general practitioner;
19. Not willing to accept information-transfer concerning participation in the study, or information regarding his health, like laboratory results, findings at anamnesis or physical examination and eventual adverse events to and from his general practitioner.