Soda Bans in Schools Have Limited Impact

State laws that ban soda in schools — but not other sweetened beverages — have virtually no impact on the amount of sugary drinks middle school students buy and consume at school, a new study shows.

The study, which looked at thousands of public school students across 40 states, found that removing soda from cafeterias and school vending machines only prompted students to buy sports drinks, sweetened fruit drinks and other sugar-laden beverages instead. In states that banned only soda, students bought and consumed sugary drinks just as frequently at school as their peers in states where there were no bans at all.

The study is among the first to directly examine the extent to which state policies on soda in schools influence students’ behavior. With obesity on the rise and teenagers getting about 15 percent of their daily calories from beverages, health groups like the Institute of Medicine have pushed for the removal of all sweetened beverages from schools, and some states have put in place all-out bans on sweetened drinks. California, for example, became the first state to ban the sale of soft drinks in grade schools, in 2003, and one city, Boston, moved earlier this year to forbid the sale and promotion of sugar-sweetened beverages and sodas on all city property.

But the sale of soft drinks in schools has become a lucrative revenue source for many school districts, and a number of states have been reluctant to eliminate them from schools. Some states have instituted only partial bans that remove sodas from schools but not Snapple, Gatorade and other sugary drinks.

In the latest study, published this week in The Archives of Pediatrics and Adolescent Medicine, researchers looked at soda and sweetened beverage consumption among roughly 7,000 fifth and eighth grade students across 40 states. The students were followed between 2004 and 2007, a time when many states and school districts were beginning to enact bans.

The researchers found that the proportion of students who purchased sugary drinks at schools in states that removed only soda — 28.9 percent — was similar to the proportion in states that had no bans against any sugary drinks at all — 26 percent. Both groups  also reported having identical levels of access to sugary beverages at school: about 67 percent in each category.

“I think definitely the biggest message is that laws need to be comprehensive to have any positive effect at all,” said Daniel R. Taber, an author of the study and postdoctoral research associate at the University of Illinois at Chicago. “The most unequivocal finding was that laws that focus on soda are just not getting it done. If you really want to create a healthier school environment, you need more comprehensive laws.”

But the study, which was funded by the National Institutes of Health and the Robert Wood Johnson Foundation, had another surprising finding. In states with policies banning all sugary drinks in schools, students had less access to them on campus, but their overall consumption of the drinks did not fall, suggesting they were getting the drinks elsewhere. Dr. Taber said that finding indicated that removing sugary drinks from school campuses, while effective, could only go so far. He said more initiatives that target sweetened beverage consumption outside of schools — like beverage taxes and regulations on their marketing to children — were needed.

“The laws did exactly what they were designed to do,” he said. “They were designed to reduce kids’ access to sweetened beverages in schools, but you can’t expect schools to do it all on their own.”

Dr. Taber said it made sense for some school districts to focus on soda at first, since it accounts for about two thirds of the calories teenagers get from sugary drinks. But that could also give some students the wrong idea about which drinks are best.

“Soda is definitely the most popular choice among kids,” he said. “But there’s a lot of misconceptions about which beverages are healthy. Many kids think beverages like Gatorade are a healthy alternative to soda.”

Midlife Weight Loss Cuts Heart Risk

Being overweight as a teenager carries a greater risk of being an overweight adult, along with an increased risk of dying of heart disease. But overweight adolescents who slim down in middle age may lower their risk, a new study shows.

Previous studies have linked being overweight as a teenager or young adult to deadly consequences later in life, including an increased risk of heart disease. But it was unclear if the risk was higher simply because heavy teenagers become heavy adults, or because being overweight or obese as a young adult causes irreversible damage.

To find out, a team of scientists at Harvard Medical School and elsewhere combed through data from the Harvard Alumni Health Study, which tracked the medical information of men who entered the university as freshmen from 1916 to 1950. The researchers gathered data on about 19,000 of the Harvard alumni who were subsequently followed in later decades, looking at their habits, heart disease risk histories and body mass indexes, among other things. The subjects were followed for up to 82 years.

The study, published on Monday in The Archives of Internal Medicine, found that the heaviest students were more likely to become overweight or obese adults. Furthermore, the men who were obese as freshmen had nearly twice the risk of dying of heart disease decades later as the men who had been of normal weight in college. A similarly increased risk was seen among the men who were overweight as freshmen.

“That simply reflects the fact that fat kids become fat adults,” said Dr. I-Min Lee, an associate professor of medicine at Harvard Medical School and an author of the study, “and that drives deaths from heart disease.”

But when the researchers factored in middle age, adjusting for the subjects’ weight at that time, they found that the risk changed. The men who started college overweight or obese but were of normal weight in middle age no longer had a higher risk of dying of heart disease.

Body mass index in middle age was a strong predictor of dying of heart disease, the study showed. Being overweight in middle age increased the risk 25 percent, and being obese raised it 60 percent.

While the study looked only at men, Dr. Lee said she believed the findings would hold for women as well, since the biological effects of overweight and obesity on heart disease risk are similar in the two sexes. In both men and women, the data linking obesity in middle age to heart disease is clear, she said.

The only other study that prospectively measured B.M.I. in both early and later life, published over 20 years ago, showed that a higher body weight in adolescence raised the risk of heart disease later in life, regardless of B.M.I. in midlife. But that study was considerably smaller and looked at only about 500 people.

Dr. Lee said that while the latest study offered good news, “it’s not that it’s not harmful to be fat when you’re younger,” since extra weight in adolescence tends to follow you into adulthood. But an editor’s note that accompanied the study ended on a more optimistic note, saying it “brings us some reason for hope that efforts to address childhood obesity are well worth it.”

“The negative influence of early B.M.I. on mortality drops out when middle-age B.M.I. is added,” the note went on. “It is never too late to adopt healthy lifestyle changes.”

Exercise Spurs Teenage Boys to Stop Smoking

For teenagers struggling to quit smoking, a new study has some advice. To break the habit, try breaking a sweat.

It showed that teenage boys who took part in a smoking cessation program and combined it with exercise were several times less likely to continue smoking than those who received only traditional anti-smoking advice. Exercise did not have a comparable effect on teenage girls; researchers aren’t sure why. But the research is among the first to show that an exercise plan for teenage smokers can help them kick two bad habits at once, smoking and inactivity, which often go hand in hand.

For young smokers, breaking the habit before adulthood can be particularly crucial. Studies show that starting as a teenager makes it much more difficult to quit later on. About 80 percent of adult smokers began their habit before turning 18. Yet every day, 3,500 teenagers light their first cigarette.

The new study, published this week in the journal Pediatrics, took place in a state with one of the worst teen tobacco problems, West Virginia, where roughly a third of all high school students are smokers. Previous studies have shown that in adults, exercise — even if it’s just a walk around the block or lifting some weights — can help curb smoking by easing withdrawal symptoms and controlling cravings when people are confronted with cigarettes and other strong cues. Since West Virginia also suffers high rates of teenage obesity, the researchers wanted to see what effect exercise could have in combating two major health threats.

“It seemed logical to address these two together,” said Kimberly Horn, a professor of community medicine at West Virginia University and the lead author of the paper. “Exercise is known to mediate factors that often co-occur with smoking cessation, like increased stress levels, weight gain, withdrawal and cravings.”

To find out, the researchers recruited 233 smokers ages 14 to 19 at West Virginia high schools, and randomly assigned each to one of three groups. Some students received a single smoking-cessation session. A second group went through a 10-week anti-smoking program called Not on Tobacco, or NOT. And those in the third group went through the NOT program and were given pedometers and counseling on starting an exercise plan, which they could then schedule on their own time.

After three months, the study found that only 5 percent of the students who got the single anti-smoking session had quit smoking. But almost twice as many who went through the 10-week program had quit. When exercise was added to the mix, the effect on boys was remarkable: 24 percent of male students in the exercise group quit smoking, while only about 8 percent in the 10-week program that did not encourage exercise had stopped. They were also more likely to have stayed away from cigarettes after six months as well. The teenage girls in the exercise group, though, were no more likely to have quit smoking than those who received only counseling on quitting smoking.

“The kids in this study were pretty hard-core smokers,” Dr. Horn said. “They smoked about a half pack a day during the week and up to a pack a day on weekends. They were pretty addicted, and most started when they were about 11 years old.”

The data did not explain why a gender divide would exist, but Dr. Horn speculated that a few things could be responsible. Teenage boys are generally more enthusiastic about engaging in vigorous exercise, and are “more confident in their ability to be physically active,” Dr. Horn said, while physical activity levels typically plummet as teenage girls get older.

“It’s puzzling to us; it was a surprise finding,” she said. “I think we also need to look at issues of self-confidence. It could be the girls started with some stronger fitness barriers to overcome than boys.”

Nonetheless, the results over all were encouraging, since getting teenagers to give up smoking — or change any potentially harmful habits — can be notoriously difficult.

“One of the important things to point out is that oftentimes people believe that kids aren’t interested in quitting smoking,” she said. “I think this demonstrates that kids can quit, they’re interested in quitting and they can be successful, given the right tools.”