30-40 healthy male subjects with a BMI between 18.5 and 24.9 kg/m2 will be tested for food preferences using a questionnaire with 141 different foods. Accordingly, a high acceptability/palatability food will be selected (average score of ≥ 7 on the 9-point hedonic scale). Two versions of the selected high palatability food will be devised by modifying it to yield the original high and the modified low acceptability versions. The two versions will differ only in palatability and will be equicaloric. Subjects who agree on the acceptability of the two versions of the food (11 subjects) will consume, at fasting, the two versions of the food in a cross over design over two sessions. Each session will include an acceptability test, using the 9-point hedonic scale, on three instances: after sampling a spoonful, eating the whole portion and after 240 min. The quantity consumed on each session will constitute 30% of the subject's resting energy expenditure. Moreover, fasting and postprandial hunger ratings and blood samples will be collected at time 0 and after 15, 30, 60, 120, 180 and 240 min of the food/meal's ingestion. The visual analogue scale will be used for huger ratings.

Inclusion Criteria:

• Gender: Male
• Age: 18-50 years
• Body Mass Index (BMI): 18.5-24.9 kg/m2
• Stable body weight for at least three months before the study with absence of any form of dieting, food restriction or other abnormal eating behaviors (to minimize effect of weight change on ghrelin status)

Exclusion Criteria:

• Smoking
• Substance abuse such as alcohol or drugs
• Medical or psychological illness
• Use of medications
• Previous gastrointestinal surgery
• History of weight fluctuation (weight loss of greater than 5% within the past 3 months)