Researchers in the U.S. who conducted a collaborative study involving the National Institute for Health and a number of academic institutions, say they have found that children who are overweight as toddlers or pre-schoolers are more likely to be overweight or obese in early adolescence.
The researchers periodically collected height and weight measurements of a sample of children, beginning at age 2 and continuing until age 12 at regular intervals and they believe their analysis provides strong evidence that being overweight in early childhood increases the risk for being overweight in later life.
Dr. Duane Alexander, the Director of NIH's National Institute of Child Health and Human Development (NICHD), which funded the study, says contrary to popular belief, young children who are overweight or obese will not use lose the extra weight simply as a result of getting older.
A large number of studies support this finding and they too have found that obesity persists from childhood, through adolescence and into adulthood. Obese adolescents become overweight adults and as a result put themselves at risk of developing cardiovascular disease, high blood pressure, stroke, and diabetes.
Principal investigator, Dr. Philip R. Nader, Professor Emeritus of Pediatrics at the University of California, San Diego, says previous studies have collected height and weight information from a few intervals in childhood and one or two intervals in later life.
In this latest study however data was collected as part of the NICHD Study of Early Child Care and Youth Development, during frequent intervals and over an extended period of time, from age 2 through age 12.
Nader says the children were born in 1991 and therefore were growing up during the current trend of overweight and obesity in the general population.
Measurements of the children's height and weight were collected when the children were ages 2, 3, 4.5, 7, 9, 11, and 12 and the researchers calculated body mass index, or BMI, for children in the study.
Children were classified as overweight if their BMI was at or above the 85th percentile in comparison to national statistics for children their age.
The researchers found that children who were overweight at least once from ages 2 to 4.5 were 5 times more likely to be overweight at age 12 when compared to children who were not overweight from ages 2 to 4.5.
The more times a child was overweight from ages 7 through 11, the greater the chances the child would be overweight at age 12 in comparison to children who were not overweight from ages 7 through 11.
Dr. Nader said that the study results suggest that parents concerned about their children's weight should speak to their children's pediatricians about helping their children establish a more healthy diet and exercise regime.
The authors also say that identifying children at risk for adolescent obesity provides physicians with an opportunity for earlier intervention with the goal of limiting the progression of abnormal weight.
The researchers found that no children in the study who were below the 50th percentile at preschool or elementary school age were overweight at age 12.
They say the findings underscore the need to maintain a healthy weight beginning in early childhood.
The study is published in September's issue of Pediatrics - Official Journal of the American Academy of Pediatrics.