Researchers at the University of North Carolina (UNC) suggested in a study, published in the October edition of the American Journal of Preventive Health, that energy intake from sweetened soft drinks and fruit drinks in the US increased by 135 percent between about 1977 and 2001.
They also claimed that over the same period energy intake from milk, which they deem "a far more nutritious beverage", dropped 38 percent.
The authors of the study - Dr. Barry Popkin, professor of nutrition and a fellow at the Carolina Population Center, and nutrition graduate student Samara Joy Nielsen - concluded that the obesity epidemic could be brought to a halt if the volume of sweetened soft drinks and fruit drinks was brought under control.
"There has been considerable controversy about the promotion of soft drinks in schools and elsewhere," Popkin said. "Extensive research on all age groups has shown that consuming these soft drinks and fruit drinks increases weight gain in children and adults."
The study discovered that between 1977 and 2001, total energy derived from soft drinks each day rose on average from 2.8 percent to 7 percent, which led to nearly a tripling of calories, and energy intake from fruit drinks per person grew from 1.1 percent to 2.2 percent. At the same time, milk supplied only five percent of energy for all age groups, down from 8 percent.
Young adults aged 19 to 39 led the way in terms of soft drink consumption, increasing their intake from 4.1 percent to 9.8 percent of total intake during the period, according to the researchers.
However, the American Beverage Association countered these claims by stating that the industry is aware of nutrition problems in the US and that low-cal alternatives and vitamin-enriched soft drinks have been produced in recent years
"Soft drink manufacturers understand that many people are struggling to keep their calories down and manage their weight, and we've introduced an array of no cal and low cal soft drinks, teas, and juice drinks to help them do that," said Kathleen Dezio, spokeswoman for the beverage association.
"The beverage industry also recognizes that many people need to increase their calcium consumption, and we've developed many new options for people who are either lactose intolerant or simply do not like to drink milk."
Dezio drew attention to the launch in the mid-1980s of calcium-fortified juices, which were soon followed by vitamin D-fortified beverages. Indeed, US sales of orange juice enriched with calcium have increased in recent years to nearly $1 billion in 2003.
The growth in this market is undoubtedly true and as consumer awareness of health and well-being issues grows, the demand for functional beverages will no doubt increase.
As Gary Roethenburgh from the British market research company Zenith suggested a few months ago: "Carbonated drinks is a very mature market, which needs to be constantly innovating. We could say fruit twists, such as Coke with lemon, were the trend for 2003. Vitamin-fortified carbonated drinks could become the trend for 2004 and beyond."