Cravings are intense desires for a particular food. Whether you're a stressed caregiver, a premenstrual or pregnant woman, or a tired-to-the-bone multitasker, you probably know the insistent gnaw of a craving -- maybe for salty chips? A fizzy drink? Cheesy pizza? Chocolate, in any form?

"Cravings are often more in our head than our belly or our body," says Beth Reardon, director of nutrition at Duke University Integrative Medicine and Caring.com senior food and nutrition editor. "The question to ask yourself isn't whether you should give into the craving, but what the craving is really about. Understanding that can help you make healthier choices that also feel satisfying."

Here's what's behind common cravings -- and how to curb them:

Craving cause #1: The pleasure system in your brain

It's no coincidence that many of the foods we crave feature three components nearly irresistible to the human palate: fat, salt, and sugar. These substances light up parts of the brain known as the reward system. Before we even taste these fatty-salty-sweet foods, the very prospect of doing so triggers associations that fuel cravings, says former FDA commissioner David Kessler, author of The End of Overeating. Merely passing the golden arches at a certain time of day can trip a rabid desire for fries.

The food industry has a name for this special quality of fat, salt, and sugar used to tantalize the brain in multisensory ways: craveability. Restaurant dishes and packaged foods -- and their marketing campaigns -- are carefully engineered to appeal to the emotions, memories, and sensory stimuli that goose the pleasure system. Your brain can develop a powerful addiction response similar to one triggered by nicotine or alcohol.

To break the craving: Curb the cues.

One of the most effective ways to help break those food associations, Kessler says, is to avoid being cued in the first place. If you crave a certain fast food, drive a different route so you don't see the restaurant. If midday M&Ms are your downfall, don't routinely keep a jar of them on your desk. Have an idea what you plan to order in a chain restaurant, so you don't have to see the mouth-watering photos on the menu.

You can also change the mental associations that trigger the reward system. Research by Australian psychologist Eva Kemps has shown that once you fixate on a particular food, mental images of it distract the brain from performing other tasks well. You can harness this effect in your favor to fight cravings, she says, by thinking of a substitute image when the urge for curly fries starts to distract you: colorful flowers, or the strong smell of eucalyptus.

You can even substitute a negative association, Kessler says: When you crave nachos, tell yourself, "That's hundreds of calories on a plate." Daydreaming of a cookies-and-cream ice cream cone? Picture yourself in a bikini or swimming trunks while eating it.