11/28/2011 06:23 pm ET Updated Jan 28, 2012

Flattening the Fizz on Kids, Excess Sugary Sodas

Along with budding musical talent, the millions of viewers who watch Fox TV's new hit The X Factor each week get a nonstop pitch for Pepsi, from the soda's logo on judges' drinking cups to hype about the winner's bonus prize: starring in a Pepsi commercial to air during the Super Bowl.

With marketing muscle like that, it's unsurprising that Americans -- many of them kids and teens -- gulp 9.4 billion cases of soft drinks annually. Sugary beverages, studies show, account for 10 to 15 percent of the total calories consumed by these groups, up 30 percent from just a decade ago. Pediatricians say that some children consume as much as 1,200 to 2,000 calories per day from soft drinks.

At the same time, as you've likely heard from First Lady Michelle Obama, being overweight or frankly obese in childhood has become epidemic, and now is the most common medical condition of children, affecting nearly 1 in 6, with 1 in 3 considered at risk. As a result, children now face a wide range of health problems that previously were only seen in adults, such as high blood pressure, type 2 diabetes and high cholesterol levels.

(A just published study in the New England Journal of Medicine offers rays of hope about obese kids, though: after examining data on 6,000 folks followed from age 11 into their 30s, investigators found that if once-obese or overweight kids had managed to shed their excess weight, their health risks were no greater than those who had normal weights; if they remained obese, in both childhood and adulthood, they faced an array of health concerns.)

How much are soft drinks to blame for porking up children? Or as New York City's anti-soda campaign asks, are kids "Pouring on the Pounds?"

The typical 12-ounce can of soda contains 40 grams of sugar, the equivalent of 10 teaspoons, and provides no nutrition. According to The American Heart Association guidelines, intake of added sugar should be limited to six teaspoons per day for women and nine for men, based on a 2,000-calorie per day diet. It does not offer specific amounts for children, but suggests that their intake should generally be less than that of adults.

Children increase their chance of becoming obese by 60 percent with each extra can or glass of sugar-sweetened beverage consumed per day, according to a widely referred to study of 548 middle-school children, conducted by researchers at Children's Hospital in Boston.

The kicker: soft drinks aren't just empty calories, they actually can make us consume more because liquids tend to not feel as filling as the same amount of calories in solid food. Soda drinkers may be hungry again in an hour and consume more.

Concern also has been raised over the phosphoric acid in soft drinks, especially colas, added for that tangy taste. At issue is whether the acid may rob bones of calcium, though the studies are few enough for results to be inconclusive. A study published in the Journal of Clinical Nutrition suggested a correlation between drinking cola and low bone mineral density in older women. Those who drank three or more colas a week had a 3.7 percent to 5.45 percent lower bone mineral density in their hip bones, compared with women who didn't drink the beverage. The more participants drank, the lower their bone density.

For kids, what be more key is that, clearly, drinking soda decreases the amount of milk they consume. Milk is the principle source of calcium; 800 mg per day -- the equivalent of three cups of milk -- are needed for optimal bone mineralization, studies show. Nearly 40 percent of peak bone mass is accumulated during adolescence. Studies suggest that even a 5 to 10 percent deficit in peak bone mass may result in a 50 percent greater lifetime prevalence of hip fractures.

Add in the long-known link between sugary drinks and tooth decay, and it's easy to see why advocates and policy makers have pushed to remove soft drinks from school cafeterias and vending machines. In 2006, former President Clinton and the American Heart Association negotiated an agreement with top soft drink manufacturers to phase out their sale of sugar-sweetened sodas in public schools.

States also have imposed their own various bans on sugar-sweetened beverages sold in schools. However, a study just published in the Archives of Pediatric and Adolescent Medicine found that none have proved effective in reducing total consumption of soft drinks. Of the 7,000 fifth- and eighth-graders interviewed in 40 states for the study, 85 percent said they'd had at least one soft drink in the past seven days.

That's one reason advocates are campaigning for more deterrents, including a campaign to impose a 10 percent excise tax on soft drinks. Advocates say that soft drink companies incurring the added tax will pass it on to consumers by raising the relatively low price of soda; that, in turn, would reduce consumption and raise money for cash-strapped governments. Proponents argue that an estimated $79 billion is spent annually on overweight and obesity, about half of which is paid by Medicare and Medicaid, at taxpayer's expense. Currently, 33 states have nominal sales taxes on soft drinks that are considered too small to alter consumption habits.

If campaigners against excess pop for kids want an indicator, though, of popular challenges they may confront with drink curbs, they may take a clue from the headline-grabbing fight in Los Angeles over flavored milks. Critics, including famed chef Jamie Oliver, have zinged the nation's second-largest school district for its unhealthy menus, including its practice of selling chocolate and strawberry milk. The district's new superintendent and school board, as part of a larger dietary overhaul, decided at summer's start to drop flavored milks -- even as critics noted that the schools still will serve fruit juices with high sugar scores.

Contemplating a switch to sugar-free soda? Noncaloric alternatives are sweetened with saccharine, aspartame or acesulfame K; they're generally considered safe but still recommended in moderation. Like regular soft drinks, sugar-free sodas contain phosphoric acid, although considerably less. Phosphoric acid also is associated with eroding tooth enamel. To minimize decay, the Association of General Dentistry suggests using a straw to reduce contact with teeth, even when drinking diet soda.

Lately, an explosion of new offerings has joined carbonated soft drinks. Cruise the supermarket and you'll find a rainbow of sleekly packaged products, including sports and energy drinks, vitamin waters, even pop fortified with vitamins and juice pouches that promise 25 percent less sugar. This barrage of beverages can be confusing.

For a quick rundown, let's start with sports drinks. These beverages, including the popular brands Gatorade and Powerade, contain carbohydrates, minerals, electrolytes and flavoring, intended to replenish water and electrolytes lost through sweating during extreme exercise. They can be helpful for prolonged, vigorous physical activities, but for most routine exercise, tap water is more than sufficient. Like soft drinks, sports drinks with their sugar content can add calories that contribute to obesity and tooth decay.

As for energy drinks, they're totally different: they contain substances that act as stimulants, such as caffeine and guarana. They shouldn't be consumed by children or teens, pediatricians say. Caffeine has been linked to detrimental health effects in children, including harming the developing neurologic and cardiovascular systems. In general, caffeine-containing beverages, including many soft drinks, should be avoided.

Companies are not required to disclose the amount of caffeine present in their energy drinks; the median amount is 99 mg, studies show. By comparison, the most caffeinated soft drink, Mountain Dew, contains 46-55 mg; followed by Diet Coke, 38-47 mg; and Dr. Pepper, with 36 mg.

Energy drinks also contain high amounts of sodium, about 7.2 percent of the recommended daily amount for children and adolescents; that is three times the amount found in soft drinks.

As for vitamin waters, they basically are soft drinks -- sugar or sugar-free -- minus the fizz, with added vitamins, though not enough to support the healthy buzz words like "defense" and "energy" touted on their labels. In fact, the Center for Science in the Public Interest is suing Coke over its claims for its VitaminWater brand.

When it comes to juices, The American Academy of Pediatrics recommends limiting intake to 6 ounces per day of 100 percent fruit juices.

Whether evaluating juice, soda, vitamin water or any other beverage, the key is to check labels for the amount of added sugar. Every four grams equals one teaspoon of sugar.

Bottom line, the best beverages for kids and teens are water, low-fat or nonfat milk and limited amounts of 100 percent fruit juices. If yours crave fizz, try offering seltzer with a slice of orange or a splash of fruit juice. Still doesn't cut it? On the occasional hot afternoon at the pool or beach, go ahead and let them crack open a cold soda. Just ensure they know it's a rare and special dessert.