Sweet or Salty: What Your Food Preferences Say about You

Sweet fiends were born that way: A craving for sweets leads infants to important, high-energy foods. Perception of sweetness has been directly linked to a specific DNA fragment in taste receptor cells, which are found in the intestines as well as the tongue. Mice that were genetically engineered to have "human" taste buds, for instance, showed a human weakness for sweets.

However, people with a high sugar threshold may actually have a low sensitivity to sweetness. These "nontasters" may have only one-third as many taste buds as "supertasters," meaning they need more sugar in foods to get the same satisfaction.

Even ants seem to know that salt is essential for life. In one study, ants in environments where salt is less abundant preferred it to sugar when given the choice.

As for people, salt is well-known for improving other tastes and masking bitterness. Because they're more sensitive to all tastes, including bad ones, supertasters may also be salt cravers.

Then again, salt lovers, you may be making up for lost time -- or sodium. Some studies suggest that premature infants who had low sodium levels at birth grow up to be salt-seeking adults.

You know the phrase "You are what you eat"? You're probably what your mother ate, too. A mother's diet while pregnant or breastfeeding can sway an infant toward developing a taste for sweet or salty foods.

Later, exposure to different foods can turn your tastes. Tastes associated with pleasant experiences are more likely to become favorites. Food cravings and choices in comfort food, for instance, can come from emotional rather than physical needs. Take chocolate: It does contain tryptophan, the amino acid needed to produce the mood-lifting chemical serotonin. But soybeans contain much more tryptophan -- and when did you last hear, "I need tofu right now"?