Lead by example. The nut doesn’t fall far from the tree. A chip off the old block. These aphorisms all fit the time-honored tradition of children adopting good behaviors—which hopefully include healthy eating habits—when these are modeled by adults, right? Not so, says a team of researchers from the Bloomberg School of Public Health at Johns Hopkins University, the National Institute on Aging and the University of Zaragoza in Spain, who reported in the December 2010 Journal of Epidemiology and Community Health that setting a solid example goes only so far. Kids are more susceptible to the influence of external factors, they found.

Led by Youfa Wang, MD, PhD, MS, the research team reviewed and assessed the degree of association and similarity between children’s and their parents’ dietary intake based on worldwide studies published since 1980. They found 24 studies meeting inclusion criteria for review and 15 for meta-regression analysis. They compared the association between parent-child pairs’ dietary intakes by type of parent-child pair (for example, mother-daughter vs. father-son), geographical region and dietary assessment method, and over time.

Most studies were based on small samples. Overall, they suggested a moderate or weak association, but findings varied remarkably, concluded Wang and colleagues. “Our meta-analysis showed that correlations varied by parent-child pairs, dietary assessment and countries. Food frequency questionnaires or mixed approaches yielded lower correlation than 24-hour recalls or food records. Child self-reported intakes showed weaker correlation and better methodology quality showed stronger correlation in fat intake (percent energy), which also became weaker over time. Overall, the resemblance is weak, and it varied considerably across studies, nutrients, foods and parent-child pairs.”

“Contrary to popular belief, many studies from different countries, including the United States, have found a weak association between parent-child dietary intake,” said Wang, lead author of the study and associate professor with the Bloomberg School of Public Health, department of international health. “This is likely because young people’s eating patterns are influenced by many complex factors, and the family environment plays only a partial role. More attention should be given to the influence of the other players on children’s eating patterns, such as that of schools, the local food environment and peer influence, government guidelines and policies that regulate school meals, and the broader food environment that is influenced by food production, distribution and advertising.” He added, “Parents need to be better empowered to be good role models and help their children eat a healthy diet.”