They add that their findings could prove important in developing new ways to improve youngsters' diets.
Using soups and crackers, sugar water and jellies, the team at the Monell Chemical Senses Center in Philadelphia tested for sweet and salt preferences in 108 children, aged between 5 and 10. The children's mothers were also tested.
Children who had a sweet tooth also liked salty tastes, the research showed, and kids tended to prefer sweeter and saltier tastes than their mothers.
Taste preferences were linked to kids' growth and development, the researchers also found. Children who were tall for their age preferred sweeter tastes, and those with higher amounts of body fat preferred saltier tastes.
It also appeared that a greater preference for sweet tastes was associated with spurts in bone growth, but this finding needs to be confirmed in a larger group of children, said the authors of the study appearing online March 17 in the journal PLoS One.
Genes played a role in whether the mothers preferred sweet tastes, but this was not the case in the children.
"There are inborn genetic differences that affect the liking for sweet by adults, but for children, other factors -- perhaps the current state of growth -- are stronger influences than genetics," study co-author Danielle Reed said in a Monell news release.
American children consume far more sugar and salt than they should, the news release pointed out. Learning more about the biology behind children's preferences for sweet and salty tastes is an important first step in finding ways to reduce their intake of sugar and salt, the researchers pointed out.
"Our research shows that the liking of salty and sweet tastes reflects in part the biology of the child," study lead author and biopsychologist Julie Mennella said in the news release.
"Growing children's heightened preferences for sweet and salty tastes make them more vulnerable to the modern diet, which differs from the diet of our past, when salt and sugars were once rare and expensive commodities," she added.
The U.S. National Library of Medicine has more about child nutrition.