The present study aims to investigate the effect of a standardized liquid breakfast containing a food grade propionate colon release form on ad libitum eating and appetite perception in healthy overweight humans using a double-blinded, randomized, cross-over study design

To determine, in healthy overweight subjects, the acute effect of a standardized liquid breakfast containing a propionate colon release form compared with placebo on appetite and GI comfort, food intake, serum glucose and insulin, plasma ghrelin, total GLP-1 and serum PYY concentrations, and plasma propionate concentrations

Inclusion Criteria:

1. Male or non-pregnant, non-lactating females, 18-60 years of age
2. Body mass index (BMI) ≥25 and <30 kg/m² at screening.
3. Unrestrained eater (Score of ≤11 on the Eating Habits Questionnaire)
4. Willing to maintain habitual diet, physical activity pattern, and body weight throughout the trial.
5. Subject is willing to abstain from strenuous exercise, and consume alcoholic drinks 24 hours before study days and during study days.
6. Willing to refrain from dietary supplement that are known to affect appetite (e.g. some herbal supplements), from prebiotic and probiotic supplements and large amounts of dietary fiber (inulin, metamucil, oat bran, etc) throughout the trial. On test days, subject agrees not to take any dietary supplements until dismissal from the GI labs. Failure to comply will result in a rescheduled test visit.
7. Absence of health conditions that would prevent fulfillment of study requirements as judged by the Investigator on the basis of medical history.
8. Understanding the study procedures and willing to provide informed consent to participate in the study and authorization to release relevant protected health information to the study investigator.
9. Subject regularly has at least one bowel movement per day

Exclusion Criteria:

1. Smokers
2. Haemoglobin measurements of <120g/L for females and <130g/L for males (as per WHO criteria for anaemia).
3. Fasting serum glucose (above or equal to 7.0mmol/L). AST, ALT, GGT and ALP >1.8 times upper limit of normal; creatinine >1.2 times upper limit of normal; fasting triglycerides >4.0 mmol/L; and electrolytes outside the normal range.
4. Known history of AIDS, hepatitis, a history or presence of clinically important endocrine (including Type 1 or Type 2 diabetes mellitus), cardiovascular (including, but not limited to, atherosclerotic disease, history of myocardial infarction, peripheral arterial disease, stroke), pulmonary, biliary or GI disorders.
5. Use of medications/dietary supplements known to influence carbohydrate metabolism, gastrointestinal function or appetite, including, but not limited to adrenergic blockers, diuretics, thiazolidinediones, metformin and systemic corticosteroids within 4 weeks of the screening visit, or with any condition which might: 1) make participation dangerous to the subject or to others, or 2) affect the results as judged by the Investigator.
6. History of propionic acidemia.
7. Major trauma or surgical event within 3 months of screening.
8. Unwillingness or inability to comply with the experimental procedures and to follow GI Labs safety guidelines.
9. Known intolerance, sensitivity or allergy to any ingredients in the study products.
10. Extreme dietary habits, as judged by the Investigator (i.e. Atkins diet, very high protein diets, etc).
11. Uncontrolled hypertension (systolic blood pressure ≥160 mm Hg or diastolic blood pressure ≥100 mm Hg as defined by the average blood pressure measured at screening.
12. Change in body weight of >3.5kg within 4 weeks of the screening visit.
13. Presence of any signs or symptoms of an active infection within 5 d prior to any test visit. If an infection occurs during the study period, test visits should be rescheduled until all signs and symptoms have resolved and any treatment (i.e. antibiotic therapy) has been completed at least 4 weeks prior to each test visit.
14. History of cancer in the prior two years, except for non-melanoma skin cancer.
15. Recent history (within 12 months of screening) or strong potential for alcohol or substance abuse. Alcohol abuse is defined as > 14 drinks per week (1 drink=12 oz beer, 5 oz wine, or 1.5 oz distilled spirits).
16. Exposure to any non-registered drug product within 30 d prior to screening.
17. Subject has donated more than 300 mL of blood during the three months prior to screening.
18. Any history of an eating disorder (eg. anorexia nervosa, bulimia nervosa, binge eating) diagnosed by a health professional