Preschoolers are more likely to develop healthier eating habits when their parents have rules about what their children can or cannot eat, according to a recent study.

Researchers from the University of Buffalo in New York found that 4-year-olds whose parents set rules about food eat healthier than those raised without such rules. The study provides new information on how toddlers' ability to self-regulate, or control, their emotional and behavioral impulses influences their eating habits two years later, depending on the presence or absence of parental food rules.

"Parents can make a difference here by training young children to self-regulate and also by setting food rules in the home,"  Xiaozhong Wen, senior author on the study, said in a statement. "We found that the combination of parental rules and young children's ability to self-regulate their behaviors works best in teaching young children to eat healthy."

For the study, researchers examined data from the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B), a federally funded, nationally representative sample conducted by the U.S. Department of Education of approximately 10,700 children born in the United States in 2001.

Using this data, researchers examined associations between self-regulation in children at 2 years and their consumption at 4 years of age of these foods: fruit juices, soda, fresh fruit, fresh vegetables, fast food, salty snacks and sweets.

 "We found that children who were able to self-regulate at 2 years old had healthy eating habits by the time they were 4 years old, so long as their parents also set rules about the right types of foods to eat," Wen said. "We found that self-regulation by itself, without parental food rules, made little difference in childrens' later eating habits."

That finding is an important one, explains Neha Sharma, a co-author and recent UB graduate from the Department of Psychology.

"It is amazing to see that a parental rule about which types of food a child can and cannot eat could have such a great impact on child eating habits," Sharma said.  "Without these boundaries set by caregivers, the benefits of high self-regulation on weight gain and childhood obesity could be diminished. This illustrates just how important parental involvement is in influencing child eating habits."

Among the unhealthy food items, soda was the one that children consumed most if their parents had no food rules.

"We found that preschoolers whose parents had no food rules drink soda about 25 percent more than children whose parents had food rules," Wen said. "We found that soda is pretty attractive to preschoolers, but soda cannot kill their hunger. It doesn't fill them up." This finding provides some insight he says, into how young children with no parental food rules begin early consumption of unhealthy foods.

The researchers are considering designing a new study to see whether improvements in toddlers' ability to self-regulate their behaviors results in their eating healthier foods.

The findings were presented on Nov. 7 at ObesityWeek 2014 in Boston.