Sugary soda may increase the effect of genes putting people at risk for obesity, according to one of several studies analyzing how the drinks influence weight gain.
People genetically predisposed to obesity were more likely to gain weight from the beverages than those without the traits, according to the study, published yesterday in an New England Journal of Medicine edition that focused on the issue. Other research showed that sports drinks were associated with added pounds among adolescents and that switching to a diet soda from a sugary one may help kids control their weight.
One in three U.S. adults and 17 percent of children are obese. Sugary beverages are the largest single caloric food source in the country, according to an editorial that accompanied the studies. This month, New York City limited the cup size that restaurants can use for sugary drinks and schools nationwide have banned the beverages.
“It is important to begin to create publishable studies to support what everyone knows,” said Steven Safyer, chief executive officer of Montefiore Medical Center in New York, who has worked to curb obesity. “We are in the eighth inning of the worst public health crisis that we have encountered in decades.”
Obesity costs the country about $147 billion a year in health-care expenses, according to the Centers for Disease Control and Prevention. If the U.S. stays on the current course, it could increase health costs $66 billion a year by 2030, according to a report earlier this week by the Trust for America’s Health and Robert Wood Johnson Foundation.
Safyer said soda is particularly harmful when it comes to obesity because it doesn’t make people feel full, eliminating the normal triggers that stop people from eating.
Parents should also be concerned about sports drinks, said Alison Field, an associate professor in epidemiology at the Harvard School of Public Health and an associate in medicine at Children’s Hospital Boston. Teenagers gained about 3.5 pounds more than their peers for each sports drink they consumed daily, according to research Field presented yesterday at the annual meeting of the Obesity Society in San Antonio, Texas.
“I don’t think all parents realize sports drinks are unhealthy,” Field said. “I’m a marathon runner, even I don’t consume 32 ounces of sports drinks when I’m running 26 miles.”
The study, funded with a grant from the National Institutes of Health, relied on self-reported surveys from about 10,000 boys and girls ages 9 to 16, taken every two years beginning in 2004. Field’s findings looked at results in a smaller set of about 4,000 of the oldest teenagers from 2008 to 2011.
“It is important to recognize that this is an abstract that was presented at a conference -- not a peer-reviewed, published study -- and we know, and science supports, that obesity is not uniquely caused by any single food or beverage,” the American Beverage Association said in a statement.
The group also said that national guidelines limit the consumption of sports drinks by high school athletes to 12-ounce containers with no more than 100 calories.
To look at the connection between genetic risk and obesity, researchers from Harvard School of Public Health analyzed databases of more than 30,000 people to compare their consumption of sugary drinks with their genetic predisposition for becoming obese. Risk was based on mutations to 32 genes associated with body mass index.
A person is considered obese when their BMI is 30 or greater, which would be 215 pounds for someone five feet, 11 inches tall.
The obesity risk for those who drank more than one sugary drink a day was about twice as high as those who had less than one serving a month, said Lu Qi, an assistant professor at the Harvard school in Boston and the senior author on the study.
The researchers didn’t look at the link between genetic risk factors and other types of foods. The finding, though, provides evidence that genes and diet may mutually influence each other, Qi said in a statement.
“This study provides strong evidence that there is a significant interaction between an important dietary factor, intake of sugar-sweetened beverages, and a genetic-predisposition score, obesity and the risk of obesity,” said Sonia Caprio, a pediatrician at the Yale School of Medicine in New Haven, Connecticut, in an editorial in the journal accompanying the studies.
In a separate report, researchers gave school children either an artificially sweetened or sugar-sweetened beverage with 104 calories for an 18-month period. Those given the higher-calorie drink gained about 2 pounds more than the sugar-free group.
Coca-Cola Co.’s chief scientific and regulatory officer Rhona Applebaum said soda has been unfairly targeted as the cause of the obesity epidemic in the U.S. She said there are many factors that are linked to weight gain and that drinks containing sugar can be a part of a healthy and balanced diet.
“Obesity is too complex to say it is the soft drinks and let’s be done with it. It is not that simple,” said Applebaum in a telephone interview. “I believe all food and beverages can fit into an active and healthy lifestyle.”