We start figuring out what flavors we like -- and dislike -- during infancy.

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How We Acquire Food Cravings

Before fast food chains and grocery stores popped up in almost every neighborhood, feeding yourself on a whim wasn't always an option. For that reason, some food psychologists believe that our innate food cravings evolved as a way to ensure that our bodies got enough energy. Granted, much of what we desire is fattening or high in calories, which may translate to obesity today. But back in the time of hunters and gatherers, such energy-dense food would help carry you until your next meal.

We acquire food cravings and the desire for high-calorie nutrition in the womb. At some point during the second trimester, a fetus's senses of taste and smell develop. While in the uterus, fetuses can distinguish between different flavors passed within the amniotic fluid [source: Monell]. Babies are also born with a preference for sweet tastes, which follows many people into adulthood when food cravings occur [source: McGowan]. Hints of a mother's diet also seep into her breast milk. Experiments with babies' tasting capabilities found that if a mother recently ate garlic, the babies drank the breast milk over longer periods of time, as though to figure out the new seasoning [source: McGowan]. In addition, the variety of a mother's diet can predict her child's palate. The more adventurous the mother's diet, the greater likelihood of the child being open to new foods [source: McGowan].

As we age, it's all about the sensory memories that we form in relationship to food. If you think your mom makes the world's best meatloaf, half of your bias likely stems from the positive associations of dinnertime with your family. After all, we only crave the foods that we've had before [source: Squires]. How can you long for crème brûlée if you've never tasted the confection? That point highlights the cultural variations in food cravings, which is why we wouldn't crave a totally foreign dish. As with the brain-reward system discussed earlier, our food cravings are physiological ways to seek out familiar pleasures.

Those familiar pleasures can also have the unwanted consequences of expanding our waistlines. For that reason, many food diets emphasize curbing food cravings and opting for healthier alternatives. But sometimes, resisting the urge isn't the prime alternative.