Its Saturday and youre out with friends, having dinner. Tonight, however, you ate too much. You shared several appetizers with the group, and you managed to eat your huge entre (why are portion sizes SO BIG'). Now its time for dessert and although your stomach is painfully pressed against your waistband, you hear yourself ordering the Mousse au Chocolat (hey, chocolate is healthy, right').

Fast-forward to Sunday night. You just prepared and ate a super healthy meal at home: Broiled herb-crusted salmon, steamed broccoli, and lemon brown rice. It was delicious and you feel totally satisfied and happy with yourself for eating so well. Yet as you are cleaning up, you find yourself nibbling on the leftover birthday cake that somehow found its way into your home. Before you know it, the cake is gone and now you are stuffed. What happened to your *healthy* dinner? Why didnt it satisfy you?

Do these scenarios ring true with you? Why do we want dessert when we just ate enough calories to theoretically energize us for days? Why would a well-balanced dinner send us straight to the cookie jar?

Actually, theres a fascinating scientific explanation that sheds light on this problem that has vexed all of us for years. It all makes perfect sense when you understand the concept of sensory specific satiety.

satiety n. The condition of being full or gratified beyond the point of satisfaction; surfeit.

Satiety is controlled by an area of the brain called the hypothalamus. This control center is sensitive to tastes (sweet, sour, salty, bitter, pungent). When one taste is satiated, your appetite for another taste, however, remains. This is sensory specific satiety.

As humans, we developed this control mechanism out of necessity, back when we had to forage and hunt for sustenance out in the wild. (In other words, way before we had the super-supermarkets like Wegmans and Whole Foods.) In the wild, our ancestors didnt know if a food was safe (i.e., it wouldnt kill you) until they tried it. So when people found a food that worked, they tended to stick with it. Hence, we love the familiar! But our nutritional needs cannot be met by eating just one food, and so we must vary our diet. According to David Katz, MD, an expert in nutrition and preventive medicine, sensory specific satiety encourages us to eat a varied diet. This mechanism is extremely helpful for balancing our desire to stick with the familiar and eat the same foods all the time. Sensory specific satiety helps us achieve that balance by encouraging us to satisfy all our taste senses.

Were not the first society to figure this out. Oriental medicine (OM) has understood this for thousands of years. Sharon Crowell, L.Ac., M.Ac., a licensed acupuncturist in Herndon, VA, explains that OM views food organically, looking at the effects that the whole food has on the body once it has been ingested. OM summarizes these effects into four categories or qualities - temperature, flavor, route, and action. A healthy diet will include a balanced combination of various foods based upon these qualities.

So how does all of this explain ordering that Mousse au Chocolat after filling up on appetizers and a huge entre? Crowell says that craving for one particular flavor (in this case, sweet) indicates an imbalance - either a deficiency of that flavor in the diet, or an excess of another flavor (e.g., salt). For example, dieting usually means staying away from sweets all day. This creates a deficiency imbalance and thus an intense craving for sweet. The sensory specific satiety theory might phrase is slightly differently by denying yourself the sweet flavor you havent satiated that sense, and so your drive for after-dinner dessert is your bodys attempt to do that. You could also have a sweet craving because you ate salty foods all day, creating a salt excess imbalance. Eating sweets is then a way to counter the salt youve eaten.

This also helps explain why many of us find that after eating healthy all day (which for many people means a sweet-free breakfast and lunch), we tend to snack heavily when we get home later in the evening. It reframes the situation its not that we lack willpower or control at the end of the day; rather, we are simply responding to our bodys need for balance.

What Can You Do?

Just knowing about sensory specific satiety is the first step to dealing with it. You can also: