The saying in the African-American community that “we’re just big-boned in our family” as a reason for being, well, overweight or even obese has taken on a whole new meaning.
The New York Times is reporting that many obese adults were set on the path by the time they were 5 years old. The new breakthrough study by the Hubert Department of Global Health and the Department of Epidemiology at Emory University in Atlanta, Ga., has determined that a third of children who were overweight in kindergarten were obese by eighth grade. And almost every child who was very obese remained that way.
Some obese or overweight kindergartners lost their excess weight, while some children of normal weight became fat over time, says the report published Thursday in the New England Journal of Medicine.
But each year, the chances became weaker and weaker that a child would shift into or out of being overweight or obese.
By age 11, changes were few: Children who were obese or overweight remained that way, and those whose weight was normal did not become fat, the Times reports.
“The main message is that obesity is established very early in life, and that it basically tracks through adolescence to adulthood,” Ruth Loos, a professor of preventive medicine at the Icahn School of Medicine at Mount Sinai in New York, who was not involved in the study, told the Times.
Obesity comes with great chronic health risks, including heat disease, high blood pressure, cancer and asthma. And the findings could be of great help in the African-American community, which has struggled mightily with obesity over the years.
Over the past 30 years, childhood obesity rates in America have nearly tripled, and today, almost one in three children in America are overweight or obese. The numbers are even higher in African American and Hispanic communities, where nearly 40 percent of the children are overweight or obese.
First Lady Michelle Obama says on her Let’s Move! site that if America don’t solve the problem of childhood obesity, one third of all children born in 2000 or later will suffer from diabetes at some point in their lives. Let’s Move! is a comprehensive initiative, launched by the first lady to solving the problem of obesity within a generation.
The results of the Emory study, however, surprised many health experts and the findings could helop reshape approaches to solving the nation’s obesity epidemic. The study suggests that efforts must start much earlier and focus more on the children at greatest risk. The findings arose from a rare study that tracked children’s body weight for years, from kindergarten through eighth grade.
Researchers say obesity may be caused by a combination of genetic predispositions to being heavy and environments that encourage overeating in those prone to it, the Times says.
But the findings do give a possible reason for why efforts to help children lose weight have often had poor results. In the past, health officials have been focused on schoolchildren instead of targeting them before they even enrolled in kindergarten.
“What is striking is the relative decrease in incidence after that initial blast” of obesity that occurs by age 5, Dr. Jeffrey P. Koplan, the vice president of the Emory Global Health Institute in Atlanta, told the Times. “It is almost as if, if you can make it to kindergarten without the weight, your chances are immensely better.”
The study involved 7,738 children from a nationally representative sample and researchers evaluated the children’s height and weight seven times from kindergarten to eighth grade.
By the time the children entered kindergarten, 12.4 percent were obese — defined as having a body mass index at or above the 95th percentile — and 14.9 percent were overweight, with a B.M.I. at or above the 85th percentile. By eighth grade, 20.8 percent were obese and 17 percent were overweight. Half of the obese kindergartners were obese when they were in eighth grade, and nearly three-quarters of the very obese kindergartners were obese in eighth grade, the Times reports. The risk that fat kindergartners would be obese in eighth grade was four to five times that of their thinner classmates, the study found.
Researchers found that race, ethnicity and family income mattered in younger children, but by the time the overweight children were 5 years old, those factors no longer affected their risk of being fat in later years, the study says.
The study did not track the children before kindergarten, but the researchers had their birth weights. Overweight or obese children often were heavy babies, at least 8.8 pounds, something other studies have also found, the Time says.
The findings also underscore the powerful influence of genetics on obesity, which can be a challenge to overcome.
Dr. Stephen O’Rahilly, an obesity researcher who is a professor of clinical biochemistry and medicine at the University of Cambridge, told the Times that genetic influences tend to show up early in life.
“We have known for 50 years that B.M.I. [Body Mass Index, which measures body fat] is highly heritable,” O’Rahilly told the Times. “Surprise, surprise, if you tend to be fat, you tend to be fat at an early age.”
But unlike height, body mass index is not inherited, Dr. Loos told the Times. And genes do not necessarily represent destiny. Exercise and a healthy diet can often reduce, but not completely overcome, the effects of genes, Loos told the Times.
To address the problem, doctors and health experts urge parents and health practitioners to tackle the problem early.
If a toddler is chunky, it shouldn’t be disregarded as simply baby fat. Some adjustments may be needed to help set the child on a healthy path, the report concludes.