CHAPTER 15

The Power of Cravings

Your senses conspire to make you desire things you know will do you harm. Why?

PART 1 Sense Memories

Your brain's limbic system generates a strong emotional response to memories of a pleasurable experience. Remember the grand holiday meals your grandmother used to make? Just seeing a picture of her holding a turkey, or catching a whiff of gravy can make your mouth water, and make you crave the full feast, even if it's the middle of July. Classic conditioning drives our cravings. Here's how it works. READ MORE

All of your senses conspire with your memory to form positive impressions of the things you crave. In a brain-scan study at the Monell Chemical Senses Center, subjects were asked simply to imagine the taste, smell and sight of their favorite foods when they spotted the names of those foods on a projection screen. On this command, the subjects' brain activity increased in the hippocampus, caudate and insula—areas also involved in drug cravings. When shown the name of a bland liquid food substitute that the research group had consumed before the study, the craving reaction did not occur. The researchers noted that when it comes to cravings, the areas of the brain associated with memory and the anticipation of having that craving satisfied, seem to play a bigger role than the rewards center, the part of the brain that releases the neurotransmitter dopamine and reinforces the use of nicotine and other drugs. LESS

PART 2 The Hormone Equation

The hormone leptin, secreted by your fat cells, sends your brain the message that you have enough energy stored and do not need to take in more. Leptin's job is to monitor energy supplies over the long haul, and help signal when you have enough fuel in storage. READ MORE

Another hormone, called ghrelin, produced mainly in the stomach, works more quickly, altering its message from meal to meal. Ghrelin rings the dinner bell in your brain, telling you to eat. More research is underway, and researchers hope to find out whether inhibiting ghrelin in overweight patients might help them lose weight by limiting their cravings. LESS

PART 3 Feed Them or Fight Them?

Research Study

Cravings and Gender

Cravings demand action. You can respond by eating, drinking or doing whatever pleasurable thing is filling your mind, or find a substitute action to distract you. Substituting something moderate for what you really want isn't easy, and might not satisfy your craving. When is it okay to give in? READ MORE

Managing your cravings is a moment by moment endeavor. Some people do it well. Others give up before really making a concerted effort. Distraction seems to be the keyword among those who successfully beat their cravings. In one study, subjects who were craving certain foods were helped by imagining nonfood sensory experiences—the appearance of a rainbow, or the scent of eucalyptus. Such exercises may seem unlikely to take your mind off of chocolate chip cookies but giving your brain something else to do can really work.

Sneaking in the occasional food treat—sweet, salty or fat—is relatively low-risk if you are following a healthful lifestyle most of the time. Also, if you have a fairly easy time managing your diet and are not prone to binge eating, you aren't at much risk of going into a junk-food spiral from tasting something you love. However, when it comes to cravings for nicotine or illicit drugs, the stakes are higher. When the brain's rewards pathway is involved, cravings have more dire consequences as you risk suffering unpleasant or even debilitating withdrawal symptoms. Working with a professional behavioral therapist to come up with successful distractions is essential when you are trying to quit smoking or taking harmful drugs.

“Our motivation to control ourselves requires recognizing that we have a problem or are at risk of having a problem, which is not easy to do,” says Dr. Michael Stein. “There's a constant interplay between appetite and self-regulation, and we're often not motivated to change unless we experience problems. By then, change is often more difficult.” LESS