Children of Obese Mothers Seem to be More Responsive to Maternal Entreaties to Eat

21/09/06 Contrary to popular wisdom, obese mothers do not push food on their children with more gusto than mothers of normal weight, a study here suggested.

However, the children of obese mothers seem to be more responsive to maternal entreaties to eat, regardless of the child's weight status, reported Julie C. Lumeng, M.D., of the University of Michigan here, and colleagues, in the September issue of The Journal of Pediatrics.

These findings emerged from a study of 71 mothers and three- to six-year-old children who were videotaped tasting four foods-two familiar and two unfamiliar. About half the children were boys, and slightly more than half were white. Maternal prompting was defined as both verbal and non-verbal encouragements and food offers. Child compliance was defined as taking a bite within five seconds of a maternal prompt.

In order to throw participants off the purpose of the study, the investigators briefly interviewed participants about their opinions of each food. The four foods, presented in random order, were a 30 g bag of potato chips, a 45 g Twinkie (these were the two familiar foods), a 30 g bag of vegetable chips (Terra Chips), and a 55 g traditional sweet Chinese moon cake.

Overall, mothers prompted their children to eat an average of 17.5 times during the four minutes each food was presented (range one to 35 times), and kids complied an average of 63% of the time (range 0% to 100%).

Obese mothers did not prompt their kids to eat significantly more often that non-obese moms (an average of 19 prompts versus 17 prompts; P=0.53).

However, children of obese mothers complied with mom's urgings to eat significantly more often than children of non-obese mothers (70% compliance versus about 60%; P=0.04). The difference in compliance was largely driven by kids following the prompts to eat the unfamiliar foods: kids with obese moms obeyed the exhortation to try the novel foods 67% of the time, compared with only 52% for the other kids (P=0.005). Both groups of kids tried the familiar foods at mom's urging about 80% of the time (P=0.61).

"The message for obese mothers is that we know you are not prompting your child to eat more often, but it appears that your child may respond more to your promptings," Dr. Lumeng said.

"In other words, little Joey will have another bite of that Twinkie if mom is obese. Now, why would that be?" Dr. Lumeng added.

At first, the researchers thought that there might be something qualitatively different about how obese mothers prompted their children to eat. But analysis of the video footage did not bear that out, Dr. Lumeng said.

Another possibility, and one more difficult to test, is that children of obese parents may have inherited genes that make them more responsive to environmental cues to eat, Dr. Lumeng speculated.

"These children may be wired to be more responsive," Dr. Lumeng suggested. Even though the children may not be overweight or obese yet, their susceptibility to cues -- such as a parent's urging, a billboard advertisement, or a television commercial for fast food -- may place them at increased risk for gaining weight just as their mothers did, she said.

If this is the case, it may be beneficial for obese parents to be aware that their children may be so wired, Dr. Lumeng said. These parents may want to be more careful about and more sensitive to environmental cues to eat that their children receive, she said.

The study also found that mothers were more likely to urge their kids to try a food if the child was younger (P<0.001), the food was unfamiliar (P=0.001), or the mother had less than a four-year college degree (P=0.005).

In children of obese mothers, low maternal education, more prompts to eat novel foods, fewer prompts to eat familiar foods, and fewer child bites of familiar foods predicted child body mass index Z score (BMIz) in the children of obese (R2 = 64%). In children of non-obese mothers, none of the covariates predicted child BMIz.

However, one mustn't jump to the conclusion that mothers with less education, a marker for socioeconomic status, are somehow feeding their children inappropriately, Dr. Lumeng said. "We have no data to back up that idea. We need to do more research on this." A limitation of the study was that it used a small number of foods, and so it is not known if the results would apply to other kinds of foods, the authors said. "It would be of particular interest to determine if the findings extrapolate to behaviors with vegetables," they added.

"A growing body of evidence suggests that maternal feeding behaviors are related to child obesity risk. Just as restrictive and controlling maternal feeding practices may contribute to obesity risk, so may prompting, particularly in children of obese mothers," the authors concluded.

"Further work is needed to determine the developmental underpinnings of this phenomenon and the limits of its effect," they said.