Mexican-American and Mexican immigrant children and adolescents have the highest obesity rates across all ethnic groups in the U.S. This may be partially related to many of them abandoning their parents’ generally healthy diet for less nutritious American fare, according to new research published in the Social Science and Medicine.

"Children in immigrant families are growing up in very different nutritional environments and very different social environments than their parents," Molly Dondero, lead author of the study, said in a statement. "Mexican diets, for example, are based much less on processed foods, although this, too, is starting to change."

Although U.S. public health officials advocate maintaining a healthy, well-balanced diet, the average American diet includes more processed foods and less fresh foods. In fact, about three-fourths of the American population follows an eating pattern low in vegetables, fruits, dairy, and oils, according to the U.S. Dietary Guidelines. This means the dietary quality of first generation children is worse than expected compared to their parents' dietary quality.

Parents typically play an important role in shaping their children's diet, but other factors such as peer pressure or trying to fit in with American peers at school or on the playground may influence this dietary change.

"There are primarily two ways that parents can influence a child's diet," said Dondero. "The first is through modeling — the children see what the parents are eating and take after them — and the second is through control, which can include what the parents prepare or permit their children to eat and even what they buy for the household."

The study, which used data from Continuous National Health and Nutrition Examination Survey that examines resemblance of diet between mothers and children, also found that children of immigrants who live in enclaves or clusters — areas whose inhabitants are culturally or ethnically distinct — usually retain their mother's dietary quality.

"Food is a big marker of identity, so perhaps children of immigrants feel pressured to fit in," Dondero explained.

If this is the case, that means typical obesity interventions and healthy eating initiatives may be less effective for Mexican immigrant families since they place the onus of the child’s eating habits on the parents and not the child himself, “or they may need to be better tailored to meet the needs of these families,” she added.

The typical American diet, which is high in saturated fat and low in nutrients, has been linked to many adverse health effects, including cancer and heart disease.

Dondero said the next step is to determine why children are eating differently from their parents.

Source: Dondero M, Hook J. Generational Status, Neighborhood Context, and Mother-Child Resemblance in Dietary Quality in Mexican-Origin Families. Social Science & Medicine. 2016.