STUDY DESIGN
This study will be a randomized crossover with three treatment periods. Subjects (n=24, approximately equal number of men and women) will be randomly assigned to a treatment sequence.
There will be three 2-day treatment periods separated by a break of \~0-4 weeks, depending on calendar conflicts such as holidays. The treatment period diets will differ in the inclusion of seeds into the recipes on the second day of each period. For all meals on Day 1 and breakfast \& lunch on Day 2 of each treatment period, participants will consume a prescribed diet provided by the Beltsville Human Nutrition Research Center. The Day 1 meals and the Day 2 breakfast will be the same for each treatment period (scaled to each participant's intake needs for weight maintenance) so that the participants will be in the same food consumption state the day before the test day. Day 2 lunch will be the treatment meal and will consist of soup, bread, and a dessert item (cookie or brownie). Each of those treatment items (soup, bread, and dessert) will be made one of three ways: (1) by our standard recipe, (2) by our standard recipe modified to include chia seeds, or (3) by our standard recipe modified to include hemp seeds. Dinner on Day 2 will be provided for carry-out and will include a large serving of a dinner entrée, a dessert, and a snack. The Day 2 dinner foods will be provided in excess, and participants will be allowed to eat as much or as little as they like, and they will bring the uneaten portions back to the Beltsville Human Nutrition Research Center the next morning, at which time they will be given a light breakfast, ending the treatment period. The Day 2 dinner items will be weighed before and after the participants eat, and the amount consumed will be recorded and compared across the different recipes to determine if the inclusion of seeds in the recipe promoted satiety. Water will be allowed ad libitum, except that consumption of liquids will not be allowed for the hour before lunch and the hour before dinner on Day 2 of each treatment period.
Participants will complete a series of hunger, fullness, food, and mood related questionnaires during the study.
STUDY PROCEDURES
Controlled feeding intervention: The Beltsville Human Nutrition Research Center will provide all meals to subjects during each 2-day treatment period. Meals will be prepared using traditional American foods with a macronutrient composition representative of a typical American diet. For meals on Day 1 and breakfast \& lunch on Day 2 of each treatment period, participants will be instructed to eat all foods and only foods provided to them, with the exception of water, coffee, and tea. Coffee and tea intake will be limited to 2 cups per day. Consumption of coffee, tea, and water will be recorded by study subjects. Dinner and snack food for Day 2 of each treatment period will be provided in excess (about 3 times the participants expected calorie needs) and the participants will consume as much or as little of those foods as they like, but they will not be allowed to consume any other foods beyond the foods provided. Alcohol consumption will not be allowed during the intervention.
Body weight: Body weight will be measured at the beginning of each treatment period.
Questionnaires: Participants will be asked to complete a series of questionnaires.
* Participants will complete a questionnaire each study day (6 days total) with questions regarding general health, medications, exercise, and beverage consumption.
* Participants will complete a Three-Factor Eating Inventory on the first morning of the first study session to determine if they are restrained eaters.
* Participants will complete a Positive and Negative Affect Schedule questionnaire before dinner on the second day of each study session to determine if mood states are different among the three study sessions.
* Participants will complete a Visual Analogue Scale assessment of the following subjective feelings at the moment of the assessment: (1) Hunger, (2) Satisfaction, (3) Fullness, (4) Prospective Food Consumption, (5) Desire to Eat something sweet, salty, savory, or fatty. This assessment will be completed on Day 2 of each session, at the following times: immediately before lunch, immediately after lunch, 1 hour after lunch, 2 hours after lunch, 3 hours after lunch, 4 hours after lunch, 5 hours after lunch, and 6 hours after lunch (which will be about 30 minutes after finishing dinner).
Food Intake: Using an analytical scale, Day 2 dinner foods for each participant will be weighed before they are provided to the participants and after the uneaten foods are returned to the Beltsville Human Nutrition Research Center. The weight of the foods will be recorded.
