Too much pop, too little nutrition

Some people deride them as "sugar water," others as "liquid candy." Never favorites with dietitians or parents, sodas are receiving more and more nutritional heat these days — and the drumbeat to run them out of schools is growing louder.

Legislation is on the march, with a bill pending in California to stringently limit soft drink sales in high schools, and other anti-soda measures under consideration in many states and school districts.

The American Beverage Assn., which represents most U.S. soft drink suppliers, is offering some concessions about school concessions. At an August meeting and in full-page ads in major newspapers, it resolved to remove sodas entirely from elementary schools, allow middle-school kids access to full-calorie sodas and fruit drinks only after school hours, and ensure that no more than 50% of the vending machine beverage offerings in high schools are soft drinks.

Why all this finger-pointing at sodas? After all, we live in an environment brimming with burgers, fries, snack cakes and chips, dealt in heftier and heftier portions to kids slumped in front of televisions and computers. What earthly effect can limiting just one item — the beverage — have on the health and weight of our offspring?

Nutrition scientists agree that getting children to move more and eat better are important. But they also say that this spotlight on sugary soft drinks makes sense. These drinks are our No. 1 dietary source of added sugars, they say. Studies connect them to body heft and nutrient shortfalls. And that moniker "liquid candy" is spot-on: The drinks are pretty much bereft of nutritional value.

"If you have to cut calories … why not start with sugar water?" says Dr. Carlos Camargo, associate professor of medicine at Harvard Medical School.

But don't just focus on sodas, experts add.

Juice drinks, sports drinks, energy drinks, calorie-laden coffee and even juice itself will help pack on pounds if imbibed to excess — and more than artificially sweetened sodas will.

The American Academy of Pediatrics recommends that school-age children limit their fruit juice to 8 to 12 ounces daily.

Electrolyte-replenishing sports drinks, which in the plan would remain in middle and high schools, are useful after very vigorous exercise but hardly needed after a 30-minute P.E. session.

"There's sort of a misperception about the role that sports drinks play in a nutritious diet," says Rachel Johnson, professor of nutrition at the University of Vermont. "If a child's thirsty, water is the best beverage."



The rise of soft drinks

Americans got their first taste of carbonated beverages well over a century ago. The first bottled sodas were produced in the 1830s, sold in corked bottles and often jazzed up with flavors such as sarsaparilla, lemon and strawberry.

The industry took off in 1892 after the invention of a cap to keep gas firmly in bottles, allowing for wide distribution.

By 1976, soft drink sales had surpassed those of milk. Since 1971, soda consumption has doubled, from an average of 25.5 gallons per person per year to more than 46 gallons in 2003.

Most of these gallons, especially among kids, are full-calorie, although in recent years there has been a small, steady increase in diet soda sales.

At the same time, a plethora of other, non-fizzy sugar-sweetened drinks have gained popularity, especially among the young: trendy teas, energy drinks and sports drinks.

Today, adults get 7% of their calories from soft drinks, according to government statistics, and teens get even more.

In still-unpublished work, Johnson's team calculated from government data that girls ages 12 to 18 receive 12.3% of their calories, and boys 13.3%, from soft drinks and sugared juice drinks (beverages containing at least some juice).

"We were amazed," says Johnson. "It was the No. 1 source of calories, including everything."

Soft drinks are also the leading source of added sugars (extra sugars put into many foods and drinks).

In 2002, a report from the federally mandated Institute of Medicine found that people consuming lots of added sugars were more likely to be deficient in micronutrients such as calcium, phosphorus and magnesium, as well as various vitamins.

On the basis of these nutrient deficiencies, the panel recommended that we limit our added sugar intake to no more than 25% of our daily calories.

Other reports, such as one in 2003 from the World Health Organization, recommended we keep our added sugar intake at 10% or lower because of its link not only to poor diet quality but also to being overweight.

Another cautionary note against sugar was sounded earlier this year in the 2005 Dietary Guidelines for Americans, which guides federal nutrition education and school lunches.

Members of the committee acknowledged that good studies linking soft drinks and excess heft are few, and the relationships when found are sometimes weak, says committee member Joanne Lupton, professor of nutrition at Texas A&M University.

Still, the committee felt there was enough evidence to suggest people lower their added sugar intake, especially from sugar-sweetened beverages, she says.

In one study the committee considered, scientists at the Children's Hospital Boston tracked 548 schoolchildren of various ethnicities for 19 months. They found that kids who increased their consumption of sugar-sweetened drinks during the study's course had slightly higher body mass indexes and were more likely to be obese, after taking into account other lifestyle differences such as levels of physical activity.

Each added 8-ounce daily serving of soft drink increased the chance of being obese by 60%, the scientists found.

In another study, British scientists tested a school-based campaign they dubbed "Ditch the Fizz." Classrooms at six elementary schools were exposed to the campaign, which used nutrition lessons and class exercises to discourage soda-drinking.

A year later, classes exposed to the anti-soda message had reduced their soda consumption by 0.6 glasses a day. Rates of overweight kids were very slightly lowered — by 0.2%.

In the class that didn't get the drink-less-soda message, consumption went up slightly — and there was a 7.5% increase in the number of overweight kids.

Some scientists worry about sugary drinks in particular because there's evidence that calories we drink — versus eat — may not be counted by our appetite regulation system.

Eat a huge cookie and you'll compensate at least somewhat for that indulgence at dinner. Drink a 52-ounce X-treme Gulp soda and you won't — or your adjustment will be smaller.

"If it's liquid and contributing calories, it's a potentially problematic component of the diet," says Rick Mattes, foods and nutrition professor at Purdue University in West Lafayette, Ind.

A few researchers further indict soft drinks because of the sugar source used to make them sweet. U.S. soft drinks contain not regular sugar (sucrose) but high-fructose corn syrup.

Critics say the rise of high-fructose corn syrup in foods tracks well with the broadening of our waistbands. Fructose, found naturally in fruits, is processed slightly differently in the body than other sugars such as glucose — and might turn to fat more easily.

Other researchers aren't convinced. They say that the amount of fructose we're exposed to via the syrup is only 55% fructose, with the rest mostly glucose. That's very similar to the 50% fructose and 50% glucose we get from sucrose.

"I see things in a pretty simple way. More 'empty' calories, less exercise equals excess calories, equals fat, whether it's actual sucrose or high-fructose corn syrup," says Camargo.



Mixed debate

Nutrition researchers generally said they were pleased that the soft drink industry was proposing some self-policing.

"I think it's a great decision and I applaud it," says Lupton.

Some were less impressed.

Margo Wootan, director of nutrition policy for the Center for Science in the Public Interest — a Washington, D.C.-based advocacy group that has been campaigning against soft drink consumption — says the proposed changes are actually slight. (In July, CSPI called on the Food and Drug Administration to place warning labels on sugary soft drinks.)

Vending machines are already rare in elementary schools, Wootan says, and sodas are for the most part absent. High schools account for most sales — and sugared sodas, juice drinks, teas and sports drinks will still be there in abundance in addition to healthier choices.

Susan Neely, the beverage association president, said the decision to offer more high school choices was made after surveying parents, beverage companies and school officials.

"The 50:50 mix is actually the appropriate way to go with older kids because we want them to have some choice," she says.

Critics say that the proposal is weaker than pending or existing legislation.

This year, legislation aimed at improving school nutrition was considered in 38 states, and 15 laws were enacted.

The Los Angeles Unified School District already has banned the sale of sodas, certain sports drinks and fruit-based, sugar-sweetened drinks composed of less than 50% fruit juice.

Soda sales are banned statewide in California elementary and middle schools, and pending California legislation backed by Gov. Arnold Schwarzenegger would limit these sales in high schools.

As the school beverage landscape slowly changes, scientists need to study kids' diets and weights to see if the measures really help, Lupton says.

"If kids are excluded from having any 100% sweetened beverages during the school day, do they make up for that on their way home from school … or do they insist that their parents buy more for them to have at home?" she says. "We really don't know how this one change in what's going to be available will affect human behavior."