Heli J. Roy | 3/19/2005 12:59:38 AM
Carbonated beverage intake has increased significantly among America’s youth over a 20-year period. One soft drink a day has been linked to 60 percent increase in the development of obesity over time, says LSU AgCenter nutritionist Dr. Heli Roy.
Mean intake of soft drinks among school-age children was twice as high in 1994-98 than in 1977-78 – that is, 12 ounces versus 5 ounces. The overall consumption of soft drinks was 48 percent higher in 1996-98 than in 1977-78. Among all soft drink consumers (children and adults), the consumption increased by 51 percent. In 1977-78 the usual amount consumed was 14 ounces versus 21 ounces in 1996-98.
Overall, total energy intake from soft drinks increased from 2.9 percent in 1977-78 to 5.9 percent in 1996-98. Increases were greater for adolescent boys in particular than girls.
There were significant changes in the source of soft drinks for children from 1977-78 to 1996-98. Although home continued to be the largest source of soft drinks in 1996-98 (48.6 percent), it did decline significantly in the 20 years from a high of 63.7 percent in 1977-78.
On the other hand, restaurants and fast-food establishments as sources of soft drinks increased more than 50 percent, from 14.4 percent in 1977-78 to 22.1 percent in 1994-98. Vending machines as sources of soft drinks also increased significantly, from 2.8 percent in 1977-78 to 4.1 percent in 1994-98, nearly 50 percent.
"The total amount of soft drinks consumed increased by a whopping 123 percent during this time," Roy says, noting that the percentage of total calories from soft drinks also increased by 103 percent during the 20 years. The most rapidly increasing sources of soft drink consumption were fast-food establishments and restaurants.
The LSU AgCenter nutritionist says that previous studies indicate that soft drink consumption may contribute to excess energy intake and the increased incidence of obesity in children and the youth. Studies have shown that liquid carbohydrates in the form of drinks are not as well regulated as solid forms of carbohydrates and may promote excess energy intake and obesity.
"Soft drinks replaced healthier choices of drinks at meals for children," Roy says, adding, "Milk and calcium intake decreased during this time and may lead to inadequate bone calcium in higher percentage of girls." Higher proportion of girls would not reach peak bone mass in adolescence and that could result in osteoporosis in later life. The USDA Food Guide Pyramid recommends 2-3 servings of milk and dairy products a day.
"For healthier alternatives in the short term and long term, replacing soft drinks with milk can lead to higher peak bone mass and reduced risk of osteoporosis in later life," Roy says.
Soft drinks also replaced other drinks such as juices, which can be healthy sources of vitamins and minerals. The food guide pyramid recommends 2-3 servings of fruits a day.
"Consuming fruit juices with vitamins C and A provides essential nutrients needed to fight infection and to serve as antioxidants for cancer prevention," Roy points out.
Results of the 20-year study were reported in the October 2003 "Journal of the American Dietetic Association" from a 1977-78 Nationwide Food Consumption Survey (NFCS) and 1994-96 Continuing Survey of Food Intake of Individuals (CSFII).
In NFCS, more than 20,000 families were contacted of whom 14,930 agreed to participate, and for the CSFII study, 20,126 families were contacted, and 16,2003 participated. Dietary intake was collected by 24-hour diet recall on two separate days three to 10 days apart.
The survey collected information about the type and amounts of consumed using USDA database codes for soft drinks. These included carbonated beverages, diet and unsweetened carbonated beverages, flavored carbonated water and carbonated juice drinks. The surveys also included information about the source from which each reported food was obtained. This way, soft drink intake could be analyzed based on source, such as home versus restaurant.