Washington:Â If you carelessly smoke around toddlers or while you are pregnant, chances are that your kids will end up with wider waist and a higher BMI by time they reach ten years of age.
 University of Montreal’s Professor Linda Pagani, who led the study, said that the children who had been intermittently or continuously exposed to smoke were likely to have waists that were up to three-fifths of an inch wider than their peers. And their BMI scores were likely to be between .48 and .81 points higher. This prospective association is almost as large as the influence of smoking while pregnant. Worldwide, 40 percent of children are exposed to secondhand smoke in their own homes.
 The study is the first to identify specifically the effect of the smoking. These findings were ascertained by comparing the behaviour of 2055 families and the outcomes for their children.
 While the increase may not seem like much, it occurs during a critical period of the child’s development known as the “adiposity rebound period.” The weight gain could therefore have serious long-lasting effects. Pagani has several explanations as to why there may be a cause and effect relationship in the association she has identified.
 Early childhood exposure to second hand smoke could be influencing endocrine imbalances and altering neurodevelopmental functioning at this critical period in hypothalamic development, thus damaging vital systems which undergo important postnatal growth and development until middle childhood, she said.Â