As you eat, your taste buds, stomach, and intestines send signals to the appetite control center in your brain. The brain processes these signals and sends out responses to make you feel satisfied. While some of these signaling pathways are fast -- others are slow.

The fastest satiety (fullness) signal comes from the stretch sensors in your stomach. These sensors are connected directly to the brain stem via the vagus nerve, and nerve signals travel almost instantaneously.

However, before your brain believes you are truly full, it also needs signals from your taste buds and small intestines. As it turns out, those signals have to follow a much longer path before reaching the brain so it takes longer. If your stomach's stretch sensors are like a bullet train connecting your stomach to your brain, the pathway from your taste buds and intestines is more like a Pony Express trail winding through the mountains.

The satiety signal that comes from your taste buds first requires the food in your mouth to be mashed into very small particles by extensive chewing and mixing with saliva. It takes a while for each bite to be chewed enough for the taste buds to recognize what's being eaten, and how much. Then, finally, signals get sent to the brain. If you chew like you're in a hot-dog eating contest, your taste buds never have a chance to register what's going on, and the signals are either weak or nonexistent.

The satiety signals from your intestines involve chemical messengers (satiety hormones) traveling through your blood stream. These signals can't be skipped like the taste buds can. Your food goes from stomach to intestine no matter what. However, it takes time.

First, food has to start trickling into your intestines. Then the hormone messengers have to weave their way throughout your circulatory system until they finally pass through the brain-blood barrier and reach the brain, where they interact with other hormones, and finally you start getting those feel-good satiety signals.

How long does it actually take? Scientific studies suggest that it takes roughly twenty minutes for all your satiety mechanisms -- stomach, intestines, taste buds -- to fully kick into gear and convince your brain that you are genuinely full.

This scientific knowledge is the basis for the weight loss tools The Savory Secret and the Pre-Fill techniques.