Adults with children 17 and under living at home eat more fat than adults in childless households, according to a new study. Their daily fat intake is about 5 grams higher.

"It's not a large amount, but if you do that every day, over time that adds up to be a lot of fat," says Helena Laroche, MD, an author of the study, published in the Jan. 4 online edition of the Journal of the American Board of Family Medicine.

For years, experts have known that parents' eating habits influence children's food intake.

Laroche decided it was time to investigate whether children's food preferences while in the household affects the parents' eating habits, specifically fat intake.

She hypothesized that adults with kids living at home would probably eat more fat for several reasons.

"There are additional time pressures on parents, advertisements of high-fat foods are aimed at children and busy parents, and there is this perception [among some parents] that children will only eat things like hot dogs and macaroni and cheese," says Laroche, an assistant professor of internal medicine and pediatrics at the University of Iowa Roy J. and Lucille A. Carver College of Medicine in Iowa City.

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Studying Fat Intake

With her colleagues, Laroche examined diet data from 6,660 adults aged 17 to 65 who had participated in a federal survey known as the National Health and Nutrition Examination Survey III, or NHANES, conducted from 1988 to 1994.

Nearly half the sample, or 48 percent, had one or more children 17 and younger at home; 52 percent had no children living at home.

Adults with kids in the house were more likely to eat such high-fat foods as cheese, ice cream, and pizza than adults without children living at home, she found.

The adults with children at home ate both more total fat and more unhealthy saturated fat.

They took in 91.4 grams of total fat a day, or about 4.9 grams more than those without children in the home.

Of that total fat, adults with children ate more saturated fat -- 29.9 grams a day compared with 28.2 grams for those without kids.

The extra saturated fat is roughly the equivalent of a slice of pepperoni pizza a day, she says.

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What's Ideal Fat Intake?

Adults should keep their total fat intake between 20 percent and 35 percent of total calories and saturated fat below 10 percent of total calories, according to the USDA Dietary Guidelines for Americans 2005.

If you eat 2,000 calories a day, that means limiting your total fat intake to 78 grams (about 700 calories) or less, with 20 grams (about 180 calories) or less of the total saturated fat.

In the study, both groups of adults ate more than 2,000 calories a day.

Those with children took in 35 percent of their calories from fat, 11.5 percent from saturated fat.

Those without kids did a bit better, taking in 34 percent of calories from fat, 11% of the calories from saturated fat.

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The study's results don't surprise Kim Blum, RD, MS, a program manager for Action for Healthy Kids in Skokie, Ill.

"A lot of times parents will buy foods they think the kids will eat," says Blum, whose nonprofit organization addresses the childhood obesity problem by fostering changes in schools.

But if parents offer fewer high-fat foods, they may well be surprised by their children's reactions, she says.

"If you put out fruits and vegetables for children at home, they will eat them," Blum insists.

She points to a U.S. Department of Agriculture program launched a few years ago that provides free fruits and vegetables for children in schools. "The kids love it," she says.

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What Can Parents Do?

Among Laroche's suggestions to cut down fat intake:

Make pizza a once-a-week treat. Eat popcorn instead of high-fat potato chips. Use olive oil instead of butter to cook. Switch children 2 and older to lower-fat milk.

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By Kathleen Doheny, reviewed by Louise Chang, MD

SOURCES: Helena Laroche, MD, assistant professor of internal medicine and pediatrics, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City. Journal of the American Board of Family Medicine,Jan. 4, 2007, online edition.Kim Blum, RD, MS, program manager, Action for Healthy Kids, Skokie, Ill.