Young mothers are more likely to have poor health habits than their peers without children, a new study from the University of Minnesota has found.

The diets of young moms include more sugar-sweetened beverages, more saturated fat and more overall calories, according to the study. Its findings also suggest that young moms tend to exercise less and have a higher body mass index (BMI) than similarly aged women who don’t have children. (BMI uses height and weight to calculate body fat.)

Young fathers, on the other hand, were found to eat no differently from men without children. Nor did they have higher BMIs. They did report exercising less than kid-free men their age, however.

These findings are important because young adults may take the poor health behaviors they establish early in parenthood with them into later life. That puts them at greater risk of obesity and their children at greater risk of developing their own poor health habits, said Jerica Berge, the study’s lead author and an assistant professor of family and community health at the U of M, in an interview last week.

Jerica Berge

“It’s not that you shouldn’t be a parent,” Berge was quick to add. “That’s not the message at all.” But parents — particularly mothers — need to be aware, she said, that the first few years of parenthood are “a high risk time” for developing unhealthy eating and exercising behaviors.

Based on Minnesota data
Surprisingly, not much previous research has looked at how parenthood changes the health behaviors of young adults, said Berge. There are some studies that have shown that parents are less likely to be physically active, and other research has found that women tend to make more healthy food choices during pregnancy. (They increase their intake of fruits, vegetables and whole grain, for example.) But not much is known about how those dietary habits fare once the baby is born.

The current study, which appears in the May issue of the journal Pediatrics, is an attempt to fill in that research gap. It used data collected from almost 1,600 young adults, including about 150 parents, who were part of Project EAT (Eating and Activity in Teens and Young Adults), a U of M project that began surveying Minnesota teens about their dietary and physical activity habits in the late 1990s. The third and most recent survey was conducted in 2008-2009, when the participants’ ages ranged from 19 to 31.

The data showed that Project EAT participants who had become parents by that third survey were more likely to be female, poor and black. Yet, even after adjusting for race, ethnicity and socio-economic status, Berge and her colleagues found that mothers reported making less healthful dietary choices than non-mothers.

More sugar and fat
Specifically, the moms took in an average of 18 percent more calories (about 400 more each day) than the non-moms. They also consumed almost twice as many sugar-sweetened drinks and they ate significantly more saturated fat than the non-moms (10.3 percent versus 9.5 of total daily calories, on average).

In addition, a closer look at the food choices of the women in Project EAT found that the non-moms were eating more dark-colored greens and other vegetables (like broccoli) than the moms. Interestingly, however, both groups ate similarly when it came to fruits, dairy products, whole grains and fiber.

These findings suggest that conflicting factors are influencing young mothers’ eating habits, Berge said. “What we think might be going on, is that although [the young mothers are] trying to model healthy eating, because of the time and effort it takes to parent, they may be relying on quick-fix meals,” Berge said. Such meals tend to be higher in fat and calories.

But why aren’t fathers also eating these less healthful foods? Berge said her study can’t answer that question, but she suggested it may be because women tend to be their children’s primary caregiver, whether or not they work outside the home, and thus may be more likely than men to snack right along with their kids on higher-calorie, higher-fat foods (whole milk rather than skim milk, for example).

The moms’ higher calorie intake would seem to explain why they tend to have a higher BMI — a mean average of 26.5 versus 25.6 for the non-moms. But another factor, said Berge, may be behind those higher BMIs: the weight the women gained during pregnancy. Most of the mothers in the study had children younger than 12 months.

The moms’ higher BMIs may also be linked to their lower levels of physical activity. They averaged about 45 minutes less of moderate-to-vigorous physical activity a week than non-moms. This was also the one health behavior in the study that the dads also tended to slip up on. They averaged about an hour-and-a-half less of exercise a week than the men with no kids.

The young dads, however, found a lot more time than the moms to exercise: The dads averaged 5.33 hours of physical activity weekly while the moms averaged only 2.36 hours.

A couple of caveats: The parents in the study were relatively young (few over the age of 30) — and so were their children. Data from older parents or from parents of older children might produce different results, said Berge. So might data from non-Minnesotan parents, she added.

A matter of time
The study wasn’t designed to identify the barriers that were keeping parents, especially moms, from exercising or making healthier food choices or keeping their weight down. But Berge suspects time constraints and fatigue may be major factors.

“I think it has a lot to do with the time demands,” said Berge. “Even when you’re pregnant, you still have control over your time. You still have time to do the healthy stuff.”

After the baby arrives, however, parents have to make trade-offs in terms of their time and energy. “That’s not bad all the time,” she said, “but there are patterns that may develop here that may be of some concern.”