By Sally Robinson and Keith Bly

All of us need to think about ways to encourage healthy lifestyles for our families. Almost 25 percent of children in the United States are overweight.

Lately, there has been a lot of discussion about soft drinks in schools and how they contribute to the increasing obesity problem in the U.S. Some legislators have even suggested a “sin” tax on high fructose foods and drinks.

In an effort to control the growing number of children that are becoming overweight in the United States, the American Academy of Pediatrics is urging school officials to remove soft drinks from vending machines in schools and replace them with healthier drinks, such as milk, 100 percent fruit juice or water.

Other suggestions for limiting access to sodas while children are in school include turning off vending machines during regular school hours and placing the machines in out-of-the-way places so they are not as noticeable. The federal government has already issued regulations that ban soft drink machines in food service areas in schools.

In the last 25 years, the number of soft drinks consumed by children has doubled, and between 56 and 85 percent of school-age children drink at least one can of soda a day. Sweetened drinks, such as cola, are the number one source of excess sugar in children’s diets.

Simply speaking, weight gain occurs when a person consumes more calories than they use and the unused calories are stored in the body as fat. The US Department of Agriculture suggests a maximum of 18 teaspoons of sugar a day for a person on a 1,600-calorie-a-day diet, which is a typical amount for a 5-year-old child. One 12-ounce serving of soda contains 150 calories and about 10 teaspoons of sugar, and children who drink more than one serving a day increase their risk of becoming overweight by 60 percent.

But obesity is not the only health risk associated with sweetened soft drinks. Many colas contain approximately 30-40 mg of caffeine. This amount is significant for children because caffeine acts as a stimulant, which can make it difficult to sleep. Caffeine also can lead to dehydration because it increases the production of urine.

The high sugar content in sweetened soft drinks also promotes tooth decay, and the acids they contain can damage the teeth by wearing away tooth enamel.

A child that drinks several soft drinks a day has lower daily intakes of important nutrients, including protein, vitamin A, vitamin D and calcium, which they would normally receive from drinking milk. This makes the problem with drinking soft drinks even worse as soft drinks have high phosphorus content, which leads to low calcium levels and causes the calcium to come out of the bones.

Sodas are not the cause of obesity in children, but they do make the risk of weight gain higher. An occasional soft drink will not harm anyone, but parents should monitor the number of sweetened soft drinks their children have and suggest healthier drinking alternatives.

Sally Robinson is a clinical professor of pediatrics at UTMB Children’s Hospital, and Keith Bly is an associate professor of pediatrics and director of the UTMB Pediatric Urgent Care Clinics. This column isn’t intended to replace the advice of your child’s physician.