Study co-authors Tracie Barnett of Ste.-Justine hospital and professor at Concordia University, Dr. Gilles Paradis of McGill University Health Center and Lisa Kakinami, a post-doctoral epidemiologist at McGill University, all in Montreal, tracked a nationally representative group of 37,577 Canadian children ages 0 to 11.
The researchers compared children whose parents were generally affectionate, had reasonable discussions about behavior and set healthy boundaries -- authoritative -- with those whose parents were strict about limits without much dialogue or affection -- authoritarian.
The research team compared parents' answers to a cross-sectional survey. They categorized parenting styles and analyzed them with respect to children's body mass index.
The children reared by authoritarian parents had a 30 percent higher chance of being obese among children ages 2 to 5 and a 37 percent higher chance among kids ages 6 to 11.
The study also found poverty was associated with childhood obesity, but parenting style affected obesity regardless of income level.
"Parents should at least be aware of their parenting style," Kakinami said. "If you're treating your child with a balance of affection and limits -- these are the kids who are least likely to be obese."
The findings were presented at the American Heart Association's Epidemiology & Prevention/Nutrition in San Francisco.