Probably a long shot, but check out Mental Measurements Yearbook if your school has a subscription.
You may already be doing this, but the first one just seems to be begging for behavioral measurement. Do a "taste test" of some cookies and see how much they chow down, maybe mix in some incentive not to eat, depending on the goal of the project. Personally, I always think its better if studies assess across various methods (e.g. self-report, behavioral, physiological) anyways, I dislike when studies rely purely on self-report when other options would fit as well (or better) with the design...it just seems lazy, and definitely weakens the conclusions you can draw.