A Study of Snacks and Satiety (feeling fed)

This study is designed to compare two types of snacks (almonds or a cereal-based snack), eaten between meals, on measures of appetite, including appetitive hormones, self-reported feelings of hunger and fullness, and food intake at a buffet meal or in the home environment. The investigators hypothesize that the acute responses of appetitive hormones to a meal challenge protocol will differ between almond and cereal-based snacks based on multivariate models of satiety that will be predictive of ad libitum food intake at a dinner meal as part of the meal challenge protocol. Further, the investigators will estimate if, under free-living conditions, self-selected and self-reported food intake will show appropriate energy compensation for the added calories of the snacks, and determine if one type of snack is superior to the other in this regard.

This study will use a randomized, parallel design that includes an almond snack intervention and a cereal-based snack intervention group. The almond intervention will be roasted, unsalted almonds at a level of 56 grams per day for 4 weeks. The cereal-based intervention will be isocaloric snacks provided in the form of a mixture of dry cereal, pretzels, and bread sticks for 4 weeks. A satiety test protocol will be done at the beginning and the end of the intervention period. Each test day will include measures of satiety responses to two standard meals, two snacks (either almonds or cereal-based snacks), and a dinner buffet. The protocol to evaluate satiety signals include tonic measures that may signal homeostasis to the brain and evaluation of episodic signals that may drive food intake In addition, other modulators of satiety will be tested including evaluation of preferences for palatable foods, self-reports of cravings and satiety using questionnaires, and perceived hunger, fullness, desire to eat.