Q. I have heard there are more changes coming in the beverage choices children have to select from vending machines in school. Do you think this will help to curb the childhood obesity epidemic?

A. About a month ago, the American Beverage Association, the trade association representing companies that manufacture and distribute nonalcoholic beverages throughout the United States, announced a set of voluntary restrictions to limit sales of soft drinks in schools. This new school vending policy will eventually stop the sales of carbonated beverages in elementary schools and remove all sugared drinks from middle schools during school hours. The policy applies only to new contracts, not existing ones, meaning it could take several years for these restrictions to be implemented in our local schools. If both the beverage supplier and the school agree, the contract could be revised and the restrictions in place sooner.

Under this new policy, the beverage industry will provide:

Elementary schools with only bottled water and 100 percent fruit juice

Middle schools with bottled water, 100 percent fruit juice, sports drinks, no-calorie soft drinks, and low-calorie juice drinks. No full-calorie soft drinks or full-calorie juice drinks will be available until after school.

High schools with bottled water, 100 percent fruit juice, sport drinks, and juice drinks. No more than 50 percent of the vending selection will be soft drinks.

While we believe this is a move in the right direction, there are still some issues with these voluntary restrictions. If you take a look at equal amounts of regular soda, fruit juice and a sports drink, you might be surprised at the comparison of the amounts of calories and carbohydrate in these various beverages.

When we look at the issue of childhood obesity, the bottom line is excessive calorie intake -- whether it is from soda, juice or sports drinks. When calorie intake is more than calorie output, weight gain is the result. Easily said, but not easily dealt with.

At right is a comparison of several popular beverages.

While fruit juice does contain significantly more nutrients than either the soda or sports drinks, it also contains more calories and sugar than the other two beverage choices when comparing equal amounts. Yes, fruit does contain natural sugar in the form of fructose, but it can contribute a great deal of calories to the diet when drunk in larger portion sizes. We would agree that fruit juice is a better choice, but in a smaller portion size. No more than 6 ounces of fruit juice a day would be a good rule of thumb. Your other servings of fruit should come from whole and canned fruits, both of which are higher in fiber than juice.

For the child who is fighting excessive weight, sports drinks should not be his or her first choice. A better way to keep children's bodies hydrated is through the consumption of water, which is always calorie free.

The bottom line is that you can't control your child's intake of beverages when they are away from home. But you can provide them with information so they can make an informed decision that will lead to good health.

If you are interested in determining the amounts of calories and more than 40 nutrients in more than 13,000 foods, the U.S. Department of Agriculture recently launched the Web site, What's in the Foods You Eat, at www.ars.usda.gov/foodsearch.