Additional outcome measures have been developed and added to the protocol.

The study uses a crossover design in which the portion size of food is varied at each meal. Across four test meals, subjects will be served four different portions of food, and intake will be determined from pre- and post-meal food weights. The first visit will be a screening visit, at which subjects will complete the consent form, have their height and weight measured, and rate the taste of the study food. Test meals will be scheduled once a week for four weeks. At visits 2-5, subjects will eat lunch and rate characteristics of the meal. At visit 6, subjects will complete various questionnaires. The objective of this study is to determine whether any individual characteristics related to satiety influence the effect of portion size on intake.

Inclusion Criteria:

• Be willing and able to travel to Penn State University Park campus weekly for meals
• Be a man or woman 18 - 60 years old
• Regularly eat 3 meals/day
• Be willing to avoid alcohol the day before and during test days
• Have a body mass index between 18.0 and 35.0 kg/m-squared
• Be willing to refrain from eating after 10 pm the evening before test sessions

Exclusion Criteria:

• A smoker
• An athlete in training
• Pregnant or breastfeeding at the time of screening
• Have taken prescription or non-prescription drugs that may affect appetite or food intake within the last 3 months
• Dislike or be unable to eat the test foods (because of allergies, intolerance, or dietary restrictions)
• Currently dieting to gain or lose weight
• Have a health condition that affects appetite
• Have participated in a similar study in our lab in the past year